Statically include @StringDef in IKE module

Bug: 146360859
Test: build, flash, boot
Test: atest FrameworksIkeTests
Change-Id: I85216a62ff56e1d635d486cd5b3c2a63ee93843c

Android.bp

@@ -592,6 +592,7 @@ filegroup {
     name: "framework-ike-shared-srcs",
     visibility: ["//frameworks/opt/net/ike"],
     srcs: [
+        "core/java/android/annotation/StringDef.java",
         "core/java/android/net/annotations/PolicyDirection.java",
         "core/java/com/android/internal/util/IState.java",
         "core/java/com/android/internal/util/State.java",