Remove no-op proguard rule

FUTURE_COPYBARA_INTEGRATE_REVIEW=https://github.com/google/nearby/pull/2240 from anayw2001:main 99c2e04f66
PiperOrigin-RevId: 597411223

sharing/android/example/app/build.gradle.kts

@@ -23,7 +23,7 @@ android {
   buildTypes {
     release {
       isMinifyEnabled = false
-      proguardFiles(getDefaultProguardFile("proguard-android-optimize.txt"), "proguard-rules.pro")
+      proguardFiles(getDefaultProguardFile("proguard-android-optimize.txt"))
     }
   }
   compileOptions {

sharing/android/example/app/proguard-rules.pro

@@ -1,21 +0,0 @@
-# Add project specific ProGuard rules here.
-# You can control the set of applied configuration files using the
-# proguardFiles setting in build.gradle.
-#
-# For more details, see
-#   http://developer.android.com/guide/developing/tools/proguard.html
-
-# 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 *;
-#}
-
-# Uncomment this to preserve the line number information for
-# debugging stack traces.
-#-keepattributes SourceFile,LineNumberTable
-
-# If you keep the line number information, uncomment this to
-# hide the original source file name.
-#-renamesourcefileattribute SourceFile