Add a snapshot of flutter/engine/src/build to our sdk

build/android/findbugs_action.gypi

Index: build/android/findbugs_action.gypi
diff --git a/build/android/findbugs_action.gypi b/build/android/findbugs_action.gypi
new file mode 100644
index 0000000000000000000000000000000000000000..e3b3d36cb196ea82fd4bed6e06fe39e677f19078
--- /dev/null
+++ b/build/android/findbugs_action.gypi
@@ -0,0 +1,22 @@
+
+{
+  'action_name': 'findbugs_<(_target_name)',
+  'message': 'Running findbugs on <(_target_name)',
+  'variables': {
+  },
+  'inputs': [
+    '<(DEPTH)/build/android/findbugs_diff.py',
+    '<(DEPTH)/build/android/findbugs_filter/findbugs_exclude.xml',
+    '<(DEPTH)/build/android/pylib/utils/findbugs.py',
+    '<(findbugs_target_jar_path)',
+  ],
+  'outputs': [
+    '<(stamp_path)',
+  ],
+  'action': [
+    'python', '<(DEPTH)/build/android/findbugs_diff.py',
+    '--auxclasspath-gyp', '>(auxclasspath)',
+    '--stamp', '<(stamp_path)',
+    '<(findbugs_target_jar_path)',
+  ],
+}