Rename mag shortcut method to notifyMagnificationShortcutTriggered.

The old name was imprecise and incorrect (it was used for more than just
button shortcut).

Bug: n/a
Test: n/a (mechanical refactor)
Flag: n/a (mechanical refactor)
Change-Id: I6422c1f165dde49cb1797334c105d49eb4a8a09e
2 files changed