Fixing tiles scrolling with arrow keys

Tiles were scrolling whenever ACTION_UP event was received on page indicator but that could also happen when user moves focus with arrows and only lands on page indicator.
Solution is to react on ACTION_UP event only after first (instead of repeated) ACTION_DOWN was received on this view as well and view doesn't lose focus in the meantime.
This logic is a bit more complicated so decided to make it internal in PageIndicator and extract this logic to separate class: LeftRightArrowPressedListener

Test: LeftRightArrowPressedListenerTest
Test: PagedTileLayoutTest
Test: navigate shade with arrows and see tiles don't scroll when focus lands on them
Fixes: 316554707
Flag: None

Change-Id: I59cfc851971b1e52f68c6a7279bd9bf1e62af159