RIL: Make RIL subclassable

Change-Id: I9144ef279ca9c8cb9e657a28342f0f4cb3e7debd

Conflicts:

	src/java/com/android/internal/telephony/RIL.java
telephony: Use reflection to create command interface (RIL class)

Change-Id: Icdc02eaa74b89dbde4ddfb989cc62481d6423312