Add flag "cloud_compilation_pm".

The flag will be used for flagging the package manager APIs for Cloud
Compilation.

(cherry picked from commit https://googleplex-android-review.git.corp.google.com/c/platform/frameworks/base/+/30255713 and https://googleplex-android-review.git.corp.google.com/c/platform/frameworks/base/+/30284506)

Bug: 377474232
Change-Id: I654181735e85bd61c269ec3ff717a89a01a3f266
Test: m
Flag: android.content.pm.cloud_compilation_pm
Merged-In: I0111fc6ef83e595a788f7900dd65743d6d90422c