[Raspberry Pi Original Development] JohnMolton94:
Thanks! I have managed to follow the steps mentioned here:

GitHub - raspberry-vanilla/android_kernel_manifest at android-13.0

Contribute to raspberry-vanilla/android_kernel_manifest development by creating an account on GitHub.

github.com

I got the following files/structure generated (in "out/common/arch/arm64/boot") after having run "BUILD_CONFIG=common/build.config.rpi4 build/build.sh" (My question is at the very end..):

/dts:
broadcom overlays

./dts/broadcom:
bcm2710-rpi-2-b.dtb bcm2710-rpi-zero-2-w.dtb bcm2837-rpi-3-a-plus.dtb
bcm2710-rpi-3-b.dtb bcm2711-rpi-400.dtb bcm2837-rpi-3-b.dtb
bcm2710-rpi-3-b-plus.dtb bcm2711-rpi-4-b.dtb bcm2837-rpi-3-b-plus.dtb
bcm2710-rpi-cm3.dtb bcm2711-rpi-cm4.dtb bcm2837-rpi-cm3-io3.dtb
bcm2710-rpi-zero-2.dtb bcm2711-rpi-cm4s.dtb

./dts/overlays:
act-led.dtbo mcp251xfd.dtbo
adafruit18.dtbo mcp3008.dtbo
adafruit-st7735r.dtbo mcp3202.dtbo
adau1977-adc.dtbo mcp342x.dtbo
adau7002-simple.dtbo media-center.dtbo
ads1015.dtbo merus-amp.dtbo
ads1115.dtbo midi-uart0.dtbo
ads7846.dtbo midi-uart1.dtbo
adv7282m.dtbo midi-uart2.dtbo
adv728x-m.dtbo midi-uart3.dtbo
akkordion-iqdacplus.dtbo midi-uart4.dtbo
allo-boss2-dac-audio.dtbo midi-uart5.dtbo
allo-boss-dac-pcm512x-audio.dtbo minipitft13.dtbo
allo-digione.dtbo miniuart-bt.dtbo
allo-katana-dac-audio.dtbo mipi-dbi-spi.dtbo
allo-piano-dac-pcm512x-audio.dtbo mlx90640.dtbo
allo-piano-dac-plus-pcm512x-audio.dtbo mmc.dtbo
android-i2c-sensor.dtbo mpu6050.dtbo
android-sdcard.dtbo mz61581.dtbo
android-usb.dtbo ov2311.dtbo
anyspi.dtbo ov5647.dtbo
apds9960.dtbo ov7251.dtbo
applepi-dac.dtbo ov9281.dtbo
arducam-64mp.dtbo overlay_map.dtb
arducam-pivariety.dtbo papirus.dtbo
at86rf233.dtbo pca953x.dtbo
audioinjector-addons.dtbo pcie-32bit-dma.dtbo
audioinjector-bare-i2s.dtbo pibell.dtbo
audioinjector-isolated-soundcard.dtbo pifacedigital.dtbo
audioinjector-ultra.dtbo pifi-40.dtbo
audioinjector-wm8731-audio.dtbo pifi-dac-hd.dtbo
audiosense-pi.dtbo pifi-dac-zero.dtbo
audremap.dtbo pifi-mini-210.dtbo
balena-fin.dtbo piglow.dtbo
camera-mux-2port.dtbo piscreen2r.dtbo
camera-mux-4port.dtbo piscreen.dtbo
cap1106.dtbo pisound.dtbo
chipdip-dac.dtbo pitft22.dtbo
cirrus-wm5102.dtbo pitft28-capacitive.dtbo
cma.dtbo pitft28-resistive.dtbo
cm-swap-i2c0.dtbo pitft35-resistive.dtbo
crystalfontz-cfa050_pi_m.dtbo pps-gpio.dtbo
cutiepi-panel.dtbo proto-codec.dtbo
dacberry400.dtbo pwm1.dtbo
dht11.dtbo pwm-2chan.dtbo
dionaudio-kiwi.dtbo pwm.dtbo
dionaudio-loco.dtbo pwm-ir-tx.dtbo
dionaudio-loco-v2.dtbo qca7000.dtbo
disable-bt.dtbo qca7000-uart0.dtbo
disable-emmc2.dtbo ramoops.dtbo
disable-wifi.dtbo ramoops-pi4.dtbo
dpi18cpadhi.dtbo rotary-encoder.dtbo
dpi18.dtbo rpi-backlight.dtbo
dpi24.dtbo rpi-codeczero.dtbo
draws.dtbo rpi-dacplus.dtbo
dwc2.dtbo rpi-dacpro.dtbo
dwc-otg.dtbo rpi-digiampplus.dtbo
edt-ft5406.dtbo rpi-ft5406.dtbo
enc28j60.dtbo rpi-poe.dtbo
enc28j60-spi2.dtbo rpi-poe-plus.dtbo
exc3000.dtbo rpi-sense.dtbo
fbtft.dtbo rpi-sense-v2.dtbo
fe-pi-audio.dtbo rpi-tv.dtbo
fsm-demo.dtbo rra-digidac1-wm8741-audio.dtbo
gc9a01.dtbo sainsmart18.dtbo
ghost-amp.dtbo sc16is750-i2c.dtbo
goodix.dtbo sc16is752-i2c.dtbo
googlevoicehat-soundcard.dtbo sc16is752-spi0.dtbo
gpio-fan.dtbo sc16is752-spi1.dtbo
gpio-hog.dtbo sdhost.dtbo
gpio-ir.dtbo sdio.dtbo
gpio-ir-tx.dtbo seeed-can-fd-hat-v1.dtbo
gpio-key.dtbo seeed-can-fd-hat-v2.dtbo
gpio-led.dtbo sh1106-spi.dtbo
gpio-no-bank0-irq.dtbo si446x-spi0.dtbo
gpio-no-irq.dtbo smi-dev.dtbo
gpio-poweroff.dtbo smi.dtbo
gpio-shutdown.dtbo smi-nand.dtbo
hd44780-lcd.dtbo spi0-0cs.dtbo
hdmi-backlight-hwhack-gpio.dtbo spi0-1cs.dtbo
hifiberry-amp100.dtbo spi0-2cs.dtbo
hifiberry-amp3.dtbo spi1-1cs.dtbo
hifiberry-amp.dtbo spi1-2cs.dtbo
hifiberry-dac.dtbo spi1-3cs.dtbo
hifiberry-dacplusadc.dtbo spi2-1cs.dtbo
hifiberry-dacplusadcpro.dtbo spi2-2cs.dtbo
hifiberry-dacplusdsp.dtbo spi2-3cs.dtbo
hifiberry-dacplus.dtbo spi3-1cs.dtbo
hifiberry-dacplushd.dtbo spi3-2cs.dtbo
hifiberry-digi.dtbo spi4-1cs.dtbo
hifiberry-digi-pro.dtbo spi4-2cs.dtbo
highperi.dtbo spi5-1cs.dtbo
hy28a.dtbo spi5-2cs.dtbo
hy28b-2017.dtbo spi6-1cs.dtbo
hy28b.dtbo spi6-2cs.dtbo
i2c0.dtbo spi-gpio35-39.dtbo
i2c1.dtbo spi-gpio40-45.dtbo
i2c3.dtbo spi-rtc.dtbo
i2c4.dtbo ssd1306.dtbo
i2c5.dtbo ssd1306-spi.dtbo
i2c6.dtbo ssd1331-spi.dtbo
i2c-bcm2708.dtbo ssd1351-spi.dtbo
i2c-fan.dtbo superaudioboard.dtbo
i2c-gpio.dtbo sx150x.dtbo
i2c-mux.dtbo tc358743-audio.dtbo
i2c-pwm-pca9685a.dtbo tc358743.dtbo
i2c-rtc.dtbo tinylcd35.dtbo
i2c-rtc-gpio.dtbo tpm-slb9670.dtbo
i2c-sensor.dtbo uart0.dtbo
i2s-dac.dtbo uart1.dtbo
i2s-gpio28-31.dtbo uart2.dtbo
ilitek251x.dtbo uart3.dtbo
imx219.dtbo uart4.dtbo
imx258.dtbo uart5.dtbo
imx290.dtbo udrc.dtbo
imx296.dtbo ugreen-dabboard.dtbo
imx327.dtbo upstream.dtbo
imx378.dtbo upstream-pi4.dtbo
imx462.dtbo vc4-fkms-v3d.dtbo
imx477.dtbo vc4-fkms-v3d-pi4.dtbo
imx519.dtbo vc4-kms-dpi-generic.dtbo
imx708.dtbo vc4-kms-dpi-hyperpixel2r.dtbo
iqaudio-codec.dtbo vc4-kms-dpi-hyperpixel4.dtbo
iqaudio-dac.dtbo vc4-kms-dpi-hyperpixel4sq.dtbo
iqaudio-dacplus.dtbo vc4-kms-dpi-panel.dtbo
iqaudio-digi-wm8804-audio.dtbo vc4-kms-dsi-7inch.dtbo
iqs550.dtbo vc4-kms-dsi-lt070me05000.dtbo
irs1125.dtbo vc4-kms-dsi-lt070me05000-v2.dtbo
i-sabre-q2m.dtbo vc4-kms-kippah-7inch.dtbo
jedec-spi-nor.dtbo vc4-kms-v3d.dtbo
justboom-both.dtbo vc4-kms-v3d-pi4.dtbo
justboom-dac.dtbo vc4-kms-vga666.dtbo
justboom-digi.dtbo vga666.dtbo
ltc294x.dtbo vl805.dtbo
max98357a.dtbo w1-gpio.dtbo
maxtherm.dtbo w1-gpio-pullup.dtbo
mbed-dac.dtbo w5500.dtbo
mcp23017.dtbo watterott-display.dtbo
mcp23s17.dtbo waveshare-can-fd-hat-mode-a.dtbo
mcp2515-can0.dtbo waveshare-can-fd-hat-mode-b.dtbo
mcp2515-can1.dtbo wittypi.dtbo
mcp2515.dtbo wm8960-soundcard.dtbo

So now, that I have run the build script and it has succeeded, what steps do I need to take to patch this built kernel to the already setup AOSP 13 build on the Raspberry Pi 4?

Do I need TWRP for that? Or is it done a different way?