Dumpstate aidl: add cancelBugreport

This allows adding a cancel method to the bugreporting API. Note that it
is implemented on the java side.

Also removed unused args from onFinished.

BUG: 111441001
Test: adb shell /data/nativetest64/dumpstate_test/dumpstate_test

Change-Id: I6a3a0d652c89dc157de4a4056ccddc40e5d6e549
diff --git a/cmds/dumpstate/tests/dumpstate_test.cpp b/cmds/dumpstate/tests/dumpstate_test.cpp
index cd9b97f..27b3130 100644
--- a/cmds/dumpstate/tests/dumpstate_test.cpp
+++ b/cmds/dumpstate/tests/dumpstate_test.cpp
@@ -61,8 +61,7 @@
   public:
     MOCK_METHOD1(onProgress, binder::Status(int32_t progress));
     MOCK_METHOD1(onError, binder::Status(int32_t error_code));
-    MOCK_METHOD3(onFinished, binder::Status(int64_t duration_ms, const ::std::string& title,
-                                            const ::std::string& description));
+    MOCK_METHOD0(onFinished, binder::Status());
     MOCK_METHOD1(onProgressUpdated, binder::Status(int32_t progress));
     MOCK_METHOD1(onMaxProgressUpdated, binder::Status(int32_t max_progress));
     MOCK_METHOD4(onSectionComplete, binder::Status(const ::std::string& name, int32_t status,