Add documentation for using dagger.android
Add documentation for using dagger.android

Closes https://github.com/google/dagger/issues/680

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=152422930

ze-pequeno/dagger,hansonchar/dagger,cgruber/dagger,ronshapiro/dagger,ronshapiro/dagger,google/dagger,ze-pequeno/dagger,dushmis/dagger,ze-pequeno/dagger,ronshapiro/dagger,hansonchar/dagger,cgruber/dagger,ze-pequeno/dagger,hansonchar/dagger,google/dagger,dushmis/dagger,google/dagger,google/dagger,cgruber/dagger