adb: switch version back to 40.
The version bump we did wasn't actually needed, since adbd doesn't
check for either feature flag we added. Revert the change and clarify
the comment suggesting the version bump when adding features.
Test: ./test_adb.py
Test: ./test_device.py
Change-Id: I92e7f392bcb36b3bf9a236f2d31ba5133de8d72a
diff --git a/adb/adb.h b/adb/adb.h
index 8c37c4b..e2911e8 100644
--- a/adb/adb.h
+++ b/adb/adb.h
@@ -59,7 +59,7 @@
std::string adb_version();
// Increment this when we want to force users to start a new adb server.
-#define ADB_SERVER_VERSION 41
+#define ADB_SERVER_VERSION 40
using TransportId = uint64_t;
class atransport;