fix for build breakage.

Change-Id: Ie324e46a79923813edd2e5e0c34ede79e6ee3eea

Author: Tsu Chiang Chuang

core/tests/bandwidthtests/src/com/android/bandwidthtest/BandwidthTest.java

@@ -142,7 +142,7 @@ protected void downloadFile() throws Exception {
      * Ensure that uploading on wifi reports reasonable stats.
      */
     @LargeTest
-    public void testWifiUpload() {
+    public void testWifiUpload() throws Exception {
         assertTrue(setDeviceWifiAndAirplaneMode(mSsid));
         uploadFile();
     }
@@ -196,7 +196,7 @@ protected void uploadFile() throws Exception {
      * accounting still goes to the app making the call and that the numbers still make sense.
      */
     @LargeTest
-    public void testWifiDownloadWithDownloadManager() {
+    public void testWifiDownloadWithDownloadManager() throws Exception {
         assertTrue(setDeviceWifiAndAirplaneMode(mSsid));
         downloadFileUsingDownloadManager();
     }