v4l2_codec2: Convert Android.mk to Android.bp

libv4l2_codec2_vda and libv4l2_code2_arcva_factory are required to be imported by
device/google/cheets/codec2/allocators/Android.bp. The allocators is also required to be imported by
device/google/cheets/codec2/vdastore/Android.bp.
Because shared library built by Android.mk is not visible by Android.bp. There is a need to convert
Android.mk in external/v4l2_codec2 to Android.bp.

Bug: 32691050
Test: build Android image

Change-Id: Ie7878393511c862c42f4d76c65c296fe8700243e