VehicleManager: use with RefBase

RefBase with sp<>

Bug: 232557259
Test: build
Merged-In: Id6b3b7e222980fd0e82b2d94ff2518e92d42a4d9
Change-Id: Id6b3b7e222980fd0e82b2d94ff2518e92d42a4d9
(cherry picked from commit 3b8e60afa3d2d6b64c25b0c171fac115ac6c107b)
1 file changed