Cannot build firebase_snippets_app for Android

[jlara310]

When I try to build the firebase_snippets_app locally, I get the following errors:

                             ^
  symbol:   method setAppCacheEnabled(boolean)
  location: class WebSettings
Note: Some input files use or override a deprecated API.
Note: Recompile with -Xlint:deprecation for details.
Note: Some input files use unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.
1 error

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':flutter_webview_plugin:compileDebugJavaWithJavac'.
> Compilation failed; see the compiler error output for details.

WARNING: This version of flutter_webview_plugin will break your Android build if it or its dependencies aren't compatible with AndroidX.
         See https://goo.gl/CP92wY for more information on the problem and how to fix it.
         This warning prints for all Android build failures. The real root cause of the error may be unrelated.

[jlara310]

Things I tried:

• Upgrading flutter_webview_plugin to 0.4.0. Same error.
• Tried using Android studio to migrate as describe in https://docs.flutter.dev/release/breaking-changes/androidx-migration, but did not work.
• Tried https://docs.flutter.dev/release/breaking-changes/androidx-migration#what-if-i-cant-use-android-studio. Created a new project and moved the dart files over. After this, I was able to tweak things a bit and run the Firestore snippets.

[thatfiredev]

Fixed in #27