Merge pull request #389 from Integral-Tech/clean-up-proguard-rules

fix: clean up proguard-rules to remove depends on google libraries

android/app/proguard-rules.pro

@@ -1,7 +1 @@
--keep class io.flutter.app.** { *; }
--keep class io.flutter.plugin.**  { *; }
--keep class io.flutter.util.**  { *; }
--keep class io.flutter.view.**  { *; }
--keep class io.flutter.**  { *; }
--keep class io.flutter.plugins.**  { *; }
 -keep class com.jcraft.**  { *; }