Fix expansion change is not reported if the notification is updated

When the notification is updated(reinflated), we should report the
expansion is visibly expanded again even it the notification of
the same key was already reported.

Test: atest ExpansionStateLoggerTest.java
Test: Manual. Send a message to myself. Observe
onNotificationExpansionChange is called. Send another message to update
the notification and go to see the notification. Observe that
onNotificationExpansionChange is called again.

Change-Id: Ie1f245c3954eafade0d81794b4722de6dfbec9dc