Add Android/data mounting along with obb mounting in vold

We should mount Android/data also, not only Android/obb.

Test: After flag is enabled, AdoptableHostTest still pass.
Bug: 148049767
Bug: 150584566
Change-Id: I26dc3756aa5843b85565495e9c2698130113f49a
Merged-In: I26dc3756aa5843b85565495e9c2698130113f49a
(cherry picked from commit d88e0900)