Whitelisting BlockedAppActivity to always launch into lock task mode so that...

Whitelisting BlockedAppActivity to always launch into lock task mode so that it does not get blocked by subsequent checks when replacing the original activity in a new task.

Test: atest -c 'CtsDevicePolicyManagerTestCases:com.android.cts.devicepolicy.MixedProfileOwnerTest#testLockTask'
Bug: b/149778685
Change-Id: If02496162a8bafe0be7adb025ff0c8e08dc6cf49