Add Android sample

[Digipom]

A sample Android app using whisper.cpp to do voice-to-text transcriptions.

To use:

1. Select a model from the whisper.cpp repository.¹
2. Copy the model to the "app/src/main/assets/models" folder.
3. Select a sample audio file (for example, jfk.wav).
4. Copy the sample to the "app/src/main/assets/samples" folder.
5. Select the "release" active build variant, and use Android Studio to run and deploy to your device.

Footnotes

1. I recommend the tiny or base models for running on an Android device. ↩

[ggerganov]

Awesome work! Thank you so much!
It works very well and this is exactly what I imagined for a demo application.

Before merging, I want to find a way to avoid the duplicated ggml/whisper source files in the example dir. Maybe some symbolic links, or some CMakeLists.txt updates. Not sure yet. If you have ideas how to avoid the duplication - let me know.

[Digipom]

Done! :) Let me know how this looks.

[ggerganov]

@Digipom Great job!

I created a discussion here: #283
And I also referenced your example from the main README of the project. Thanks!

[Digipom]

Thanks to you for creating this project! :)