Remove unused frameworks/base/Android.mk

All Android.mk files under `frameworks/base` have been converted to
Android.bp. The original `$(call first-makefiles-under ...` is no
longer necessary, so this file can be deleted.

Bug: 322732227
Test: CIs
Change-Id: I62206fe284379db55ce4ac08fd6c0e4982e55a05
1 file changed