Files added:
- README.android
- README.version
- Android.mk

Files changed (To remove guava dependency):
- client/java/com/google/rappor/Encoder.java
- client/java/com/google/rappor/HmacDrbg.java

Test: make rappor

Bug: 64932482
Change-Id: I0c77a7a53557f56d925d53e731ba4fc4c730b2b8