Revert "Revert "Adding multiple provider support in AbstractMast..."

Revert "Revert "Adding tests for multiple provider support in Ab..."

Revert submission 17060491-revert-17008428-cherrypick-multi-provider-cloudsearch-2yrjp5zxz1-WHCUFOAJWF

Reason for revert: Fixing the breakage in ag/17065868
Reverted Changes:
Ic57ef1339:Revert "Adding multiple provider support in Abstra...
I22cfed884:Revert "Adding tests for multiple provider support...

Test: atest CloudSearchServiceTestCases
Change-Id: I531fd57e5eab6c5106037558c0b6b8e81c629ec0