Replace material-dialogs with AppCompat AlertDialog

[msfjarvis]

This PR removes the material-dialogs dependency in the library by switching its uses to the AppCompat AlertDialog.

This has multiple benefits:

• Prevents classpath pollution for users of this library who do not use material-dialogs
• Reduces APK size for the abovementioned users
• Allows the dialogs shown by the library to follow the theming set up by the apps using it

Fixes #33

Screenshots

API 29:

[anggrayudi]

Great work! 👍
BTW, I have the following requests:

1. Change the target branch to release/0.7.0
2. Please put test results (screenshots) into the PR description on API 19, 21 and 29.

[msfjarvis]

The API 19 emulator was prohibitively slow on my machine so I could not manage to install the sample on it, and on API 21 the app crashed on launch immediately:

Stacktrace

AndroidRuntime  D  Shutting down VM
                E  FATAL EXCEPTION: main
                E  Process: com.anggrayudi.storage.sample, PID: 3513
                E  java.lang.RuntimeException: Unable to start activity ComponentInfo{com.anggrayudi.storage.sample/com.anggrayudi.storage.sample.activity.MainA
                   ctivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String java.io.File.getPath()' on a null object referen
                   ce
                E      at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2298)
                E      at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
                E      at android.app.ActivityThread.access$800(ActivityThread.java:144)
                E      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
                E      at android.os.Handler.dispatchMessage(Handler.java:102)
                E      at android.os.Looper.loop(Looper.java:135)
                E      at android.app.ActivityThread.main(ActivityThread.java:5221)
                E      at java.lang.reflect.Method.invoke(Native Method)
                E      at java.lang.reflect.Method.invoke(Method.java:372)
                E      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
                E      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
                E  Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String java.io.File.getPath()' on a null object refere
                   nce
                E      at com.anggrayudi.storage.file.DocumentFileCompat.getStorageIds(DocumentFileCompat.kt:457)
                E      at com.anggrayudi.storage.sample.StorageInfoAdapter.<init>(StorageInfoAdapter.kt:32)
                E      at com.anggrayudi.storage.sample.activity.MainActivity.onCreate(MainActivity.kt:65)
                E      at android.app.Activity.performCreate(Activity.java:5937)
                E      at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
                E      at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251)
                E      ... 10 more
                Process  I  Sending signal. PID: 3513 SIG: 9

I've attached the screenshot for API 29.

[anggrayudi]

Can you try to add filterNotNull() into DocumentFileCompat at line 456? Let's see whether it could fix the issue.

[msfjarvis]

It does fix the crash, but I can't attach a screenshot for it since storage access is automatically granted on API 21 so the code path for the dialogs is never hit.