Disable SELinux before executing AppStartup Test

Test: Tested Locally
Bug: 192271282
Change-Id: I1e1af3e637366b0a9c4566311a77afedaf71935d

tools/catbox-tradefed/res/config/catbox-preparer.xml

diff --git a/tools/catbox-tradefed/res/config/catbox-preparer.xml b/tools/catbox-tradefed/res/config/catbox-preparer.xml
index 0ca2571..b2e367f 100644
--- a/tools/catbox-tradefed/res/config/catbox-preparer.xml
+++ b/tools/catbox-tradefed/res/config/catbox-preparer.xml
@@ -14,6 +14,9 @@
      limitations under the License.
 -->
 <configuration description="CATBOX Target Preparer Configuration">
+  <!-- Target Preparers - Disable SELinux before Test Execution -->
+  <target_preparer class="com.android.tradefed.targetprep.DisableSELinuxTargetPreparer" />
+
   <!-- Target Preparers - Clean the Device after Test Execution -->
   <target_preparer class="com.android.tradefed.targetprep.DeviceCleaner">
     <option name="disable" value="true" />