Remove AAPT1 support

AAPT2 is used everywhere now, remove support for AAPT1.  Also
removes dpi_specific_apk.mk, it was never updated to use AAPT2
and has been generating bad APKs (resource ID mismatch between
the dex files and the resources) since AAPT2 was made the default
in May 2018 (I9b67fd2a9b3234798b2aac879b5242c2097b3863).

Bug: 80450981
Test: m checkbuild
Change-Id: I2ff768897360ff866dbae5562455bab22be270f7
Merged-In: I2ff768897360ff866dbae5562455bab22be270f7