Prevent race condition between SavedQuery and Query Loader

SearchFragment and SavedQueryLoader share a loader manager
and had been using the same loader id for different
loaders.

Occaisionally (in monkey tests) two loaders with the same
IDs would be started and crash when they finished.

The loaders now have different IDs.

Change-Id: I11e9b7365605fbcef44cf7d2323183415422f5c8
Fixes: 64756515
Test: robotests