crespo: libcamera: fix issues with the aosp camera in 4.3

- Do not send command to camera unless preview is started
  (fix 4.3 AOSP camera crash)
- Send touch AF command regardless of previous state
  (required to actually trigger touch AF at the new area)

https://github.com/CyanogenMod/android_device_samsung_aries-common/commit/153090a8285c6e9193d88b86008e7f2e506ba177

Change-Id: I0c00dc426ea6028d6687280c4d5826b25319ad8a