[Wear PAS] Add Setting for if PAS is enabled

Skip-CP-To-Master: this setting will be used only while phenotype is unavailable. We should not need this setting after moving from T.

Bug: 280889422
Test: Built and flashed. Verified in logs that toggling the option triggered an attempt to schedule the monitor job. Verified that PAS was correspondigly enabled/disabled.
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:15eab7a0a9110587104d71fc81bd6d68e315be2b)
Change-Id: I0e52aac7a64f79cf068eabcbad5dfd7bd13c2a0f