Expose ContactSelectionActivity to Instant Apps

This is needed for Instant Apps to be able to use the Contacts Picker

Bug: 34468723
Test: cts-tradefed run commandAndExit cts-dev -m
CtsAppSecurityHostTestCases -t android.appsecurity.cts.EphemeralTest
Test: Manually verified that ACTION_PICK works from an Instant App

Change-Id: Id091fd0172d450078807f5e78518027a77896898