Fix java.lang.AbstractMethodError: androidx.window.sidecar.SidecarInterface$SidecarCallback.onDeviceStateChanged

The crash was reported for `Microsoft Surface Duo`, which would affect some samsung and other devices as well, mainly dual screens/foldables. It was caused by androidx:window library that has been used by termux-shared since v0.115 having a typo in its proguard rules which didn't stop the removal of the required method for release builds (not debug) by proguard.

The library has been patched and fix should be available on next version but doing an emergency patch now for termux as well.

For people who are getting the crash should set `disable-terminal-margin-adjustment=true` in `termux.properties` created as per instructions in the link below and then start termux again and see if it fixes the issue. If you had termux installed before updating, you should be able to directly access the `~/.termux/termux.properties` file with SAF.

https://github.com/termux/termux-app/issues/1896#issuecomment-766188879

------

**Crash Message**:
```
abstract method "void androidx.window.sidecar.SidecarInterface$SidecarCallback.onDeviceStateChanged(androidx.window.sidecar.SidecarDeviceState)"
```

### Stacktrace

```
java.lang.AbstractMethodError: abstract method "void androidx.window.sidecar.SidecarInterface$SidecarCallback.onDeviceStateChanged(androidx.window.sidecar.SidecarDeviceState)"
at androidx.window.sidecar.MicrosoftSurfaceSidecar.updateDeviceState(MicrosoftSurfaceSidecar.java:159)
at androidx.window.sidecar.MicrosoftSurfaceSidecar$1.deviceStateChanged(MicrosoftSurfaceSidecar.java:192)
at android.vendor.screenlayout.service.IWindowExtensionCallbackInterface$Stub.onTransact(IWindowExtensionCallbackInterface.java:94)
at android.os.Binder.execTransactInternal(Binder.java:1021)
at android.os.Binder.execTransact(Binder.java:994)

```

https://issuetracker.google.com/issues/189001730
https://android-review.googlesource.com/c/platform/frameworks/support/+/1757630

app/proguard-rules.pro

@@ -10,3 +10,8 @@
 -dontobfuscate
 #-renamesourcefileattribute SourceFile
 #-keepattributes SourceFile,LineNumberTable
+
+# Temp fix for androidx.window:window:1.0.0-alpha09 imported by termux-shared
+# https://issuetracker.google.com/issues/189001730
+# https://android-review.googlesource.com/c/platform/frameworks/support/+/1757630
+-keep class androidx.window.** { *; }