Move DispatchersModule to /di/modules (2/3)

Move DispatchersModule to /di/modules so that it's easier to find all
the modules which provide instances of different classes.

Test: Build success
Bug: 315709229
Flag: None
Change-Id: I5540a2b88bda0b2ef003c549df3f6d2c9fedae2e
1 file changed