This is the root bug for all UMA tracking for the Peeking Launcher

Add UMA for:
State Transitions:
Peeking -> fullscreen transition via swipe
Peeking -> fullscreen transition via the all apps chevron
Tapping the launcher body to close (from all states)
Launcher Transitions

Grouping/Folders:
Entering folder view.
Number of apps in folders.

Pagination:
Touching pagination indicators in ALLAPPS
Clicking pagination indicators in ALLAPPS

Search Usage:
Length of search query in PEEKING
Length of search query in FULLSCREEN

Search Result Clicks:
SearchResult click/touches from HALF 
SearchResult click/touches from Fullscreen_search

Searches initiated:
Searches from peeking mode(laptop)
Searches from Fullscreen mode(laptop)
Searches from Fullscreen mode(tablet)

Deleting Text in the searchbox:
Tapping the launcher body to delete active search
Tapping the X button to delete active search
Deleting all text by the backspace key
Keyboard Focusing the X button to delete active search

Launching suggested apps:
Launching suggested apps from Peeking
Launching suggested apps from ALL APPS