Enable minify to reduce apk size

app/build.gradle

@@ -33,7 +33,8 @@ android {
 
     buildTypes {
         release {
-            minifyEnabled false
+            minifyEnabled true
+            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
         }
         debug {
             // Use a different app ID for debug to allow its coexistence with release builds

app/proguard-rules.pro

@@ -0,0 +1,7 @@
+-keepattributes LineNumberTable,SourceFile
+-renamesourcefileattribute SourceFile
+-dontobfuscate
+
+# some classes are required by the native code, keep them all for now
+-keep class com.emanuelef.remote_capture.** { *; }
+-keep class com.pcapdroid.mitm.** { *; }