Introduce realtime log viewer

This contains a share button and a save button, the former using a
custom content provider.

Co-authored-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Harsh Shandilya <me@msfjarvis.dev>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

ui/src/main/AndroidManifest.xml

@@ -31,6 +31,7 @@
         android:banner="@mipmap/banner">
 
         <activity android:name=".activity.TunnelToggleActivity" android:theme="@style/NoBackgroundTheme"/>
+
         <activity android:name=".activity.MainActivity">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
@@ -58,6 +59,19 @@
             android:screenOrientation="fullSensor"
             tools:replace="screenOrientation" />
 
+        <activity android:name=".activity.LogViewerActivity"
+            android:label="@string/log_viewer_title">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN"/>
+            </intent-filter>
+        </activity>
+
+        <provider
+            android:name=".activity.LogViewerActivity$ExportedLogContentProvider"
+            android:authorities="${applicationId}.exported-log"
+            android:exported="false"
+            android:grantUriPermissions="true" />
+
         <receiver android:name=".BootShutdownReceiver">
             <intent-filter>
                 <action android:name="android.intent.action.ACTION_SHUTDOWN" />