Initial commit of "HostStubGen" (Ravenwood)

See tools/hoststubgen/README.md for the directory structure...

This CL contains:
- The HostGenTool.

- Libraries to build / run host side tets. (helper-*/ directories)

- Currently we expose ArrayMap and Log to the host side, but we also need to
expose a lot more classes that the tests usee.

- Some sample tests. (test-framework/ and test-tiny-framework/)

Sample tests contain very small tests for ArrayMap and Log.

- This version doen't loa JNI code yet. It still uses the Java substitution
for Log's native methods.

This is because `libandroid_runtime` seems to have a lot of obscure dependencies,
and using `libandroid_runtime` could cause obscure build errors when someone
make chages to any of direct/indirect dependencies.

- Current version doesn't use any Java annotations to control what are exposed
on the host side. Instead, we use `framework-policy-override.txt`, which is
easier to change. (because changing the file wouln't require rebuilding
framework-minus-apex.jar.)

- Currently we expose ArrayMap and Log to the host side, but we also need to
expose a lot more classes that the tests usee. See the `framework-policy-override.txt`
file.

Test: ./scripts/run-all-tests.sh
Bug: 292141694
Change-Id: If149e26aa919d17a0b82dacc78f31bd79fbb110b
diff --git a/Android.bp b/Android.bp
index 431f0b9..8eebcbb 100644
--- a/Android.bp
+++ b/Android.bp
@@ -163,6 +163,12 @@
         //same purpose.
         "//external/robolectric:__subpackages__",
         "//frameworks/layoutlib:__subpackages__",
+
+        // This is for the same purpose as robolectric -- to build "framework.jar" for host-side
+        // testing.
+        // TODO: Once Ravenwood is stable, move the host side jar targets to this directory,
+        // and remove this line.
+        "//frameworks/base/tools/hoststubgen:__subpackages__",
     ],
 }
 
@@ -405,6 +411,7 @@
         "audiopolicy-aidl-java",
         "sounddose-aidl-java",
         "modules-utils-expresslog",
+        "hoststubgen-annotations",
     ],
 }