If we depend on legacyIntent, then TextClassifierService implementations
will have to always popuplate a deprecated field.
To avoid breaking legacy clients, the returned legacyOnClickListener should
represent the first pendingIntent (i.e. primary action) that was parcelled.
Bug: 78340399
Test: atest CtsViewTestCases:TextClassificationManagerTest
Test: atest FrameworksCoreTests:TextClassificationTest
Test: manual check with a TCS that only sets non-deprecated fields vs a
legacy TC client
Change-Id: I41d27a65f1ede6369dd2a66d92b2210edb0d11e2
ba196c5a3d