RESTRICT AUTOMERGE Prevent root from getting unverified attributions from non system apps

Similar to shell, system server, and other packages, the root UID
bypasses attribution tag registration requirements. This can be
exploited by a malicious proxy app.

Also fixes a bug which caused an unverified proxy app's attribution tag
to be erroneously called "valid" if "finishProxyOp" was called for a
non-system proxy app, and one of the special proxied apps

Bug: 416491779
Test: atest AppOpsMemoryUsageTest
Flag: EXEMPT see bug
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:ab99cde450cf900767a641ddcf71f4a42e771334)
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:47347f85086c7cc3d29998f213caad0c91ad025c)
Merged-In: I9b44465554e10b803bc9b4ab76130aaf9933f605
Change-Id: I9b44465554e10b803bc9b4ab76130aaf9933f605