Allow signature spoofing for microG Companion/Services

This patch enables signature spoofing when the following conditions are
met:
* Build is debuggable (userdebug/eng)
* Package name is com.android.vending or com.google.android.gms
* Package is signed with microG release keys
* Fake signature is correct

Additionally, we let these apps be forceQueryable if they so desire.

Change-Id: I8fc82ed266a2cc59636b662c7ea7e29c94f509b5