ADD: ProGuard rules for release build.

Author: oasisfeng

.gitignore

@@ -14,5 +14,3 @@ build
 
 # OSX files
 .DS_Store
-
-proguard-rules.pro

build.gradle

@@ -30,6 +30,14 @@ android {
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
     }
 
+    buildTypes {
+        release {
+            minifyEnabled true
+            shrinkResources true
+            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
+        }
+    }
+
     aaptOptions {
         noCompress "apk"
     }

proguard-rules.pro

@@ -0,0 +1,24 @@
+# Add project specific ProGuard rules here.
+# By default, the flags in this file are appended to flags specified
+# in E:/Android/sdk/tools/proguard/proguard-android.txt
+# You can edit the include path and order by changing the proguardFiles
+# directive in build.gradle.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# Add any project specific keep options here:
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+#   public *;
+#}
+
+# Shrink only
+-dontobfuscate
+
+# More debugging info (file name & line number)
+-renamesourcefileattribute SourceFile
+-keepattributes SourceFile,LineNumberTable