Revert "copy symsearch and disableversioncheck to recovery-ramdisk and add custom init.recovery.rc to automatically load them"

This reverts commit 049928f361c42dde289d2863ad89fa88da0129ea.
Revert "use custom_bootimg.mk so we can use inline kernel-build for modules but use the prebuilt kernel to boot"

This reverts commit 4d5e8a30504a6fab01b1409264957c41aebfdaee.
add custom kernel.mk to use prebuilt kernel after compiling modules

Change-Id: Ib5772f3cb19a4c4a3e0016f5dc8b67f2cd22c46c