[MTE] Allow system_app to write memtag property.

(cherry picked from commit 39f29f758ebeb4d7a5edc6151d8b24c815cd99aa)
(we need this cherry picked on android12-tests-dev to allow OEMs to
backport the associated feature without violating the neverallow
CTS)

Bug: 206895651
Merged-In: I6463965c094b9b3c4f3f70929a09e109ee9c84b9
Change-Id: I6463965c094b9b3c4f3f70929a09e109ee9c84b9
2 files changed