rework battery level verbose logging

also fixed mock expectations

Change-Id: Iee1f486c6cf65032f092dbcdd314a48781f37184
diff --git a/tests/src/com/android/tradefed/invoker/TestInvocationTest.java b/tests/src/com/android/tradefed/invoker/TestInvocationTest.java
index 6a4662a..90c860e 100644
--- a/tests/src/com/android/tradefed/invoker/TestInvocationTest.java
+++ b/tests/src/com/android/tradefed/invoker/TestInvocationTest.java
@@ -118,6 +118,7 @@
 
         mStubConfiguration.setLogOutput(mMockLogger);
         EasyMock.expect(mMockDevice.getSerialNumber()).andStubReturn(SERIAL);
+        EasyMock.expect(mMockDevice.getIDevice()).andStubReturn(null);
         mMockDevice.setRecovery(mMockRecovery);
 
         EasyMock.expect(mMockBuildInfo.getBuildId()).andStubReturn("1");