Add new ExpandableNotificationRowController.

This reverts commit 372729e8a2d6534eea46d4215d33b758d87e74e6.

The original commit was fine, but the commit it was built upon had
an issue that needed to be fixed. Checking them both back in now.

Bug: 147245740
Test: atest SystemUITests
Change-Id: I94de0f1feec4d2f11e66a2c38b94e4f874503585
19 files changed