Timer UX polish

Bug: 17481223
Bug: 17479934

- Vertically align Timers and Stopwatch
- Set statusbar color on timer fullscreen alert
- Make Timer label not clickable on fullscreen alert
- Adjust Timer page indicator end margin
- Remove unused methods
- Move Timer cancel button to the left-button spot

Change-Id: If0e1d000b9ffeffa7fc84ef61b92a18640cc6120