Enable proguard and wire up rules

Signed-off-by: Harsh Shandilya <me@msfjarvis.dev>

app/build.gradle

@@ -46,6 +46,8 @@ android {
                     arguments "-DANDROID_PACKAGE_NAME=${android.defaultConfig.applicationId}"
                 }
             }
+            minifyEnabled true
+            proguardFiles getDefaultProguardFile("proguard-android.txt"), "proguard-rules.pro"
         }
         debug {
             applicationIdSuffix ".debug"

app/proguard-rules.pro

@@ -0,0 +1,5 @@
+# Squelch all warnings, they're harmless but ProGuard
+# escalates them as errors.
+-dontwarn sun.misc.Unsafe
+# We're OSS anyway and who doesn't love a readable log
+-dontobfuscate