Set fake rpc backend impl for TestLinuxBridgeAgent

Fixes bug 1153845

Change-Id: I692bfc16dbd52dacd2a9418f0bd63c3143a25025
Fix issues with db pooling

Fixes bug 1157045

Change-Id: I1b0ea5b18b3d75dc3d047975b234275420af189c
Merge "Set fake rpc backend impl for TestLinuxBridgeAgent" into milestone-proposed