[AOD RONs] Center text in redacted notifs

When a notification is redacted, it only has the top line showing the
app name and timestamp. In this case, the text has to be centered
vertically.

Also fixed the height being to tall in this case due to the actions
container.

Fix: 417591288
Test: checked that both redacted and unredacted notifications are
aligned correctly and have the right bottom space
FLag: android.app.ui_rich_ongoing

Change-Id: I6b4619b1f9bf436d7d61ff83ff76a256f1ccd565