Move all files to natural position.

app/src/main/java/org/thoughtcrime/securesms/MainActivity.java

@@ -0,0 +1,45 @@
+package org.thoughtcrime.securesms;
+
+import android.os.Bundle;
+
+import androidx.annotation.NonNull;
+
+import org.thoughtcrime.securesms.util.DynamicNoActionBarTheme;
+import org.thoughtcrime.securesms.util.DynamicTheme;
+
+public class MainActivity extends PassphraseRequiredActionBarActivity {
+
+  private final DynamicTheme  dynamicTheme = new DynamicNoActionBarTheme();
+  private final MainNavigator navigator    = new MainNavigator(this);
+
+  @Override
+  protected void onCreate(Bundle savedInstanceState, boolean ready) {
+    super.onCreate(savedInstanceState, ready);
+    setContentView(R.layout.main_activity);
+
+    navigator.onCreate(savedInstanceState);
+  }
+
+  @Override
+  protected void onPreCreate() {
+    super.onPreCreate();
+    dynamicTheme.onCreate(this);
+  }
+
+  @Override
+  protected void onResume() {
+    super.onResume();
+    dynamicTheme.onResume(this);
+  }
+
+  @Override
+  public void onBackPressed() {
+    if (!navigator.onBackPressed()) {
+      super.onBackPressed();
+    }
+  }
+
+  public @NonNull MainNavigator getNavigator() {
+    return navigator;
+  }
+}