Added skip of android.backup.cts.BackupQuotaTest#testQuotaExceeded if LocalTransport is not present

Skip the test if LocalTransport is not present.

Bug: 30120602
Change-Id: I3015d5d4103f984c4be1a8ceadad30f2e8fd2e53
diff --git a/tests/backup/src/android/backup/cts/BackupQuotaTest.java b/tests/backup/src/android/backup/cts/BackupQuotaTest.java
index 01c368a..bec28c7 100644
--- a/tests/backup/src/android/backup/cts/BackupQuotaTest.java
+++ b/tests/backup/src/android/backup/cts/BackupQuotaTest.java
@@ -46,14 +46,18 @@
 
     private static final int SMALL_LOGCAT_DELAY = 1000;
 
+    private boolean localTransportIsPresent;
     private boolean wasBackupEnabled;
     private String oldTransport;
 
     @Override
     protected void setUp() throws Exception {
         super.setUp();
+        localTransportIsPresent = hasBackupTransport(LOCAL_TRANSPORT);
+        if (!localTransportIsPresent) {
+            return;
+        }
         // Enable backup and select local backup transport
-        assertTrue("LocalTransport should be available.", hasBackupTransport(LOCAL_TRANSPORT));
         wasBackupEnabled = enableBackup(true);
         oldTransport = setBackupTransport(LOCAL_TRANSPORT);
     }
@@ -61,12 +65,17 @@
     @Override
     protected void tearDown() throws Exception {
         // Return old transport
-        setBackupTransport(oldTransport);
-        enableBackup(wasBackupEnabled);
+        if (localTransportIsPresent) {
+            setBackupTransport(oldTransport);
+            enableBackup(wasBackupEnabled);
+        }
         super.tearDown();
     }
 
     public void testQuotaExceeded() throws Exception {
+        if (!localTransportIsPresent) {
+            return;
+        }
         exec("logcat --clear");
         exec("setprop log.tag." + APP_LOG_TAG +" VERBOSE");
         // Launch test app and create file exceeding limit for local transport