Creatae StagingApp class for staging build type

frontend/android/build.gradle

@@ -105,9 +105,6 @@ android {
         exclude 'META-INF/*.version'
         exclude 'META-INF/proguard/*.pro'
     }
-    sourceSets {
-        staging.java.srcDirs += 'src/debug/java'
-    }
 }
 
 dependencies {

frontend/android/proguard-rules-production.pro

@@ -1,6 +1,6 @@
 # Remove LogCat Tree anyway
 -assumenosideeffects class io.github.droidkaigi.confsched2019.App {
-    public *** enableLogCatLogging();
+    public *** enableLogcatLogging();
 }
 
 # Remove Android Log's methods
@@ -11,6 +11,7 @@
     public static *** v(...);
     public static *** w(...);
     public static *** wtf(...);
+    public static *** println(...);
 }
 
 # Remove log methods which CrashlyticsTree doesn't support

frontend/android/src/staging/AndroidManifest.xml

@@ -6,7 +6,7 @@
     >
 
     <application
-        android:name=".DebugApp"
+        android:name=".StagingApp"
         tools:replace="name"
         >
     </application>

frontend/android/src/staging/java/io/github/droidkaigi/confsched2019/StagingApp.kt

@@ -0,0 +1,28 @@
+package io.github.droidkaigi.confsched2019
+
+import com.facebook.stetho.Stetho
+import com.squareup.leakcanary.LeakCanary
+
+class StagingApp : App() {
+    override fun onCreate() {
+        super.onCreate()
+        setupLeakCanary()
+        setupStetho()
+    }
+
+    private fun setupLeakCanary() {
+        if (LeakCanary.isInAnalyzerProcess(this)) {
+            return
+        }
+        LeakCanary.install(this)
+    }
+
+    private fun setupStetho() {
+        Stetho.initializeWithDefaults(this)
+    }
+
+    override fun setupLogHandler() {
+        super.setupLogHandler()
+        enableLogcatLogging()
+    }
+}