Add cts shim apex with prebuilts

Cts shim apex is typically installed as a prebuilts.
Because prebuilt apexes don't support installing as "flattened", it
would fail to be installed when PRODUCT_INSTALL_EXTRA_FLATTENED_APEXES
is turned on(e.g. GSI targets)

com.android.apex.cts.shim.v1_with_prebuilts is a new target which can be
used in that case.

For example, we can explicitly add
com.android.apex.cts.shim.v1_with_prebuilts.flattened to
PRODUCT_PACKAGES so that flattened cts shim apex is installed in
/system_ext.

Bug: 158169437
Bug: 159392784
Test: m com.android.apex.cts.shim.v1_with_prebuilts.flattened
      # should install the prebuilts of shim APKs
Change-Id: Ie4104b4fb92096677cf101000ff492fb8cedc0fd
2 files changed