SnapdragonCamera: SecureCamera to be singleInstance

Change launch mode to singleInstance when it's launched from
the lock screen. This allows the camera to start fresh when
gallery is stacked on top.

Change-Id: I1a9fdb0e6b1c8e9382001c7a2c257b9209d23b62
CRs-Fixed: 961044
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index cd9a415..f92a3f5 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -121,7 +121,7 @@
             android:excludeFromRecents="true"
             android:icon="@mipmap/ic_launcher_camera"
             android:label="@string/snapcam_app_name"
-            android:launchMode="singleTop"
+            android:launchMode="singleInstance"
             android:logo="@mipmap/ic_launcher_gallery"
             android:taskAffinity="com.android.camera.SecureCameraActivity"
             android:theme="@style/Theme.Camera"