Offer baseline `RavenwoodFlagsValueProvider`.

Many test authors are starting to use `CheckFlagsRule` across suites
like CTS, so instead of recommending that they use `null` when on
Ravenwood, offer them a clear behavior that is either "all-on" or
"all-off".

Eventually we'll explore providing default flag values on Ravenwood,
but let's get something cleaner available now.

Bug: 318841620
Test: ./frameworks/base/ravenwood/run-ravenwood-tests.sh
Change-Id: Id234a375426fad38f64d3a999339bb720eae84bf
diff --git a/ravenwood/Android.bp b/ravenwood/Android.bp
index e535f0a..178102e 100644
--- a/ravenwood/Android.bp
+++ b/ravenwood/Android.bp
@@ -86,6 +86,21 @@
     jarjar_rules: ":ravenwood-services-jarjar-rules",
 }
 
+// Separated out from ravenwood-junit-impl since it needs to compile
+// against `module_current`
+java_library {
+    name: "ravenwood-junit-impl-flag",
+    srcs: [
+        "junit-flag-src/**/*.java",
+    ],
+    sdk_version: "module_current",
+    libs: [
+        "junit",
+        "flag-junit",
+    ],
+    visibility: ["//visibility:public"],
+}
+
 // Carefully compiles against only test_current to support tests that
 // want to verify they're unbundled.  The "impl" library above is what
 // ships inside the Ravenwood environment to actually drive any API
@@ -95,10 +110,12 @@
     srcs: [
         "junit-src/**/*.java",
         "junit-stub-src/**/*.java",
+        "junit-flag-src/**/*.java",
     ],
     sdk_version: "test_current",
     libs: [
         "junit",
+        "flag-junit",
     ],
     visibility: ["//visibility:public"],
 }