Add flashing screen

app/src/main/res/layout/activity_flash.xml

@@ -0,0 +1,56 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    android:orientation="vertical"
+    android:background="@android:color/black"
+    tools:context="com.topjohnwu.magisk.FlashActivity">
+
+    <include layout="@layout/toolbar"/>
+
+    <HorizontalScrollView
+        android:layout_weight="1"
+        android:layout_width="match_parent"
+        android:layout_height="0dp">
+
+        <android.support.v7.widget.RecyclerView
+            android:id="@+id/flash_logs"
+            android:layout_width="wrap_content"
+            android:layout_height="match_parent"
+            app:layoutManager="android.support.v7.widget.LinearLayoutManager">
+
+        </android.support.v7.widget.RecyclerView>
+
+    </HorizontalScrollView>
+
+    <LinearLayout
+        android:id="@+id/button_panel"
+        style="?android:buttonStyle"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:layout_marginTop="10dp"
+        android:background="@android:color/darker_gray"
+        android:orientation="horizontal"
+        android:visibility="gone">
+
+        <Button
+            android:id="@+id/no_thanks"
+            style="?android:borderlessButtonStyle"
+            android:layout_width="0dp"
+            android:layout_height="50dp"
+            android:layout_weight="1"
+            android:text="@string/close" />
+
+        <Button
+            android:id="@+id/reboot"
+            style="?android:borderlessButtonStyle"
+            android:layout_width="0dp"
+            android:layout_height="50dp"
+            android:layout_weight="1"
+            android:text="@string/reboot" />
+
+    </LinearLayout>
+
+</LinearLayout>

app/src/main/res/layout/list_item_flashlog.xml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<TextView
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/textView"
+    android:layout_width="wrap_content"
+    android:layout_height="wrap_content"
+    android:fontFamily="monospace"
+    android:textColor="@android:color/white"
+    android:textSize="10sp" />

app/src/main/res/values/strings.xml

@@ -133,6 +133,7 @@
     <string name="manager_update_title">New Magisk Manager Update Available!</string>
     <string name="manager_download_install">Press to download and install</string>
     <string name="magisk_updates">Magisk Updates</string>
+    <string name="flashing">Flashing</string>
 
     <!--Settings Activity -->
     <string name="settings_general_category">General</string>