Let GrantCredentialsPermissionActivity opt out edge-to-edge

This is a temporary solution to prevent the layout issue while
enabling the feature flag of the edge-to-edge enforcement.

We still need to make the activity handle insets properly later.

Fix: 344828280
Bug: 309578419
Flag: com.android.window.flags.enforce_edge_to_edge
Test: presubmit
Change-Id: Ia69d99c210d5f7826b7554a93ce1d74cbecbd751