Catch Throwable instead of Exception.

AssertionFailedError is a Throwable and hence some logs which will
help debug the failures are not printed.

Bug: 38384021
Test: Verified that when the test throws AssertionFailedError, required
      logs are printed.

Change-Id: I6cc8e0172b8e30d268a50bdf9281d6828fc74810

tests/cts/hostside/app/src/com/android/cts/net/hostside/AbstractRestrictBackgroundNetworkTestCase.java

@@ -812,7 +812,7 @@ abstract class AbstractRestrictBackgroundNetworkTestCase extends Instrumentation
         executeSilentShellCommand("am set-inactive " + TEST_APP2_PKG + " " + enabled );
         try {
             assertAppIdle(enabled); // Sanity check
-        } catch (Exception e) {
+        } catch (Throwable e) {
             final String afterStats = getUsageStatsDump();
             Log.d(TAG, "UsageStats before:\n" + beforeStats);
             Log.d(TAG, "UsageStats after:\n" + afterStats);