opengl: tests: Add explict android:exported flag to manifests

After Android S+, it's required to add android:exported flag on manifests
if an intent filter is defined[1]. However, it's missing on the
manifests of these opengl tests which are targeting to current sdk
version leads to installation failures for these APKs. Fix it by adding
required android:exported flag.

[1]: https://android.googlesource.com/platform/frameworks/base/+/c4e90ac06ad3e0fd2af9e3864742e2d1199a8cdd

Test: These APKs are installed successfully on Android 12 devices.

Bug: 215940253
Change-Id: Ia95a46cc55103e7f075900acd237b41699f4cbd0
diff --git a/opengl/tests/gl2_cameraeye/AndroidManifest.xml b/opengl/tests/gl2_cameraeye/AndroidManifest.xml
index c53f7be..a4674e1 100644
--- a/opengl/tests/gl2_cameraeye/AndroidManifest.xml
+++ b/opengl/tests/gl2_cameraeye/AndroidManifest.xml
@@ -26,7 +26,7 @@
     <uses-feature android:name="android.hardware.camera.autofocus" />
     <uses-feature android:glEsVersion="0x00020000" />
     <application android:label="@string/gl2cameraeye_name">
-        <activity android:name="GL2CameraEye">
+        <activity android:name="GL2CameraEye" android:exported="true">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN"/>
                 <category android:name="android.intent.category.LAUNCHER"/>