Add instrumentation data to host proto lib

Add instrumentation data proto to host proto lib and add a few comment
to am instrument.
Test: no test needed

Change-Id: Ibbb0394dcf0ad27b53d5c97104456798863ce82c

Android.mk

@@ -1558,6 +1558,7 @@ LOCAL_PROTOC_FLAGS := \
 LOCAL_SOURCE_FILES_ALL_GENERATED := true
 LOCAL_SRC_FILES := \
     tools/streaming_proto/stream.proto \
+    cmds/am/proto/instrumentation_data.proto \
     $(call all-proto-files-under, core/proto) \
     $(call all-proto-files-under, libs/incident/proto)
 include $(BUILD_HOST_JAVA_LIBRARY)

cmds/am/src/com/android/commands/am/Instrument.java

@@ -47,6 +47,16 @@ import java.util.Locale;
 
 /**
  * Runs the am instrument command
+ *
+ * Test Result Code:
+ * 1 - Test running
+ * 0 - Test passed
+ * -2 - assertion failure
+ * -1 - other exceptions
+ *
+ * Session Result Code:
+ * -1: Success
+ * other: Failure
  */
 public class Instrument {
     public static final String DEFAULT_LOG_DIR = "instrument-logs";