Error : No Launcher activity found!
최초 시작할 액티비티를 바꿀 때, Manifest에 이하의 태그를 추가해 줌.
<activity android:name=".CameraActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
