feat: generate proguard rule file for android

[amrbashir]

This PR requires #926

What kind of change does this PR introduce?

• Bugfix
• Feature
• Docs
• Code style update
• Refactor
• Build-related changes
• Other, please describe:

Does this PR introduce a breaking change?

• Yes
• No

Checklist

• This PR will resolve [bug] Method Not Found RustWebView setAutoPlay tauri#6694
• A change file is added if any packages will require a version bump due to this PR per the instructions in the readme.
• I have added a convincing reason for adding this feature, if necessary
• It can be built on all targets and pass CI/CD.

Other information

[lok52]

Hi! After including the suggested proguard file, I am getting another error.

04-16 14:58:12.683 18445 18445 E AndroidRuntime: java.lang.NoSuchFieldError: no "Lbencher/tauri_bencher/RustWebView;" field "m_webview" in class "Lbencher/tauri_bencher/MainActivity;" or its superclasses
04-16 14:58:12.683 18445 18445 E AndroidRuntime: 	at android.os.MessageQueue.nativePollOnce(Native Method)
04-16 14:58:12.683 18445 18445 E AndroidRuntime: 	at android.os.MessageQueue.next(MessageQueue.java:335)
04-16 14:58:12.683 18445 18445 E AndroidRuntime: 	at android.os.Looper.loopOnce(Looper.java:161)
04-16 14:58:12.683 18445 18445 E AndroidRuntime: 	at android.os.Looper.loop(Looper.java:288)
04-16 14:58:12.683 18445 18445 E AndroidRuntime: 	at android.app.ActivityThread.main(ActivityThread.java:7872)
04-16 14:58:12.683 18445 18445 E AndroidRuntime: 	at java.lang.reflect.Method.invoke(Native Method)
04-16 14:58:12.683 18445 18445 E AndroidRuntime: 	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:548)
04-16 14:58:12.683 18445 18445 E AndroidRuntime: 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:936)
04-16 14:58:12.688   586  1994 E ActivityManager: App crashed on incremental package bencher.tauri_bencher which is 100% loaded.