Set compatible_with=appengine on GAE targets

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=128475519

java/google/registry/tools/server/BUILD

@@ -10,6 +10,7 @@ java_library(
     srcs = glob([
         "*.java",
     ]),
+    compatible_with = ["//buildenv/target:appengine"],
     deps = [
         "//java/com/google/common/annotations",
         "//java/com/google/common/base",