Reland: Creates an Android.bp with prebuilt_etc for permission XMLs.

These will be included by APEXes in followup changes.

Changes from original attempt
I60d435f629e9ca25f6da98bac960a12d6d762fe1:
- Removes unused android.software.app_compat_overrides.xml
- Adds soc_specific to the defaults so that these modules all
  go to /vendor
- Changes each module to use a `prebuilt.xml` suffix to prevent
  warnings about duplicate/overridden build outputs. This has
  no effect on how these files are ingested by SystemConfig.

Bug: 197787336
Bug: 198635611
Test: (Used in APEXes in followup changes)
Change-Id: I3aa922c88ba91b948da6c6c1f4611044e97fa03d
Merged-In: I3aa922c88ba91b948da6c6c1f4611044e97fa03d