MediaRouter: Update a member list of route group dynamically in MRCD

When a route group descriptor is changed, MRCD needs to apply the
changed information about the current route. This change makes the
member route list up-to-date. Insertion/deletion animation will be
addressed with a separate change.

Bug: 26026701
Change-Id: I2c923a1a810b83a8fa91e8fb976b787c515f5972
1 file changed