Expose PeopleActivity to Instant Apps

PeopleActivity is used for EDIT and INSERT actions.

Test: cts-tradefed run commandAndExit cts-dev -m
CtsAppSecurityHostTestCases -t
android.appsecurity.cts.EphemeralTest#testExposedSystemActivities

Change-Id: I6117600c91174f84f14d49471c988d48646584a0
(cherry picked from commit d8b90389)