Add android_sdk_repo_host to build platform-tools&build-tools

The Android SDK has been built with Make up until now, monolithically,
then split up into several sdk-repo zip files for different purposes.
The Mac and Windows SDKs really only need to contain the platform-tools
and build-tools pieces, but due to this monolithic sdk zip, we had to
build the whole SDK first.

This adds an `android_sdk_repo_host` module that can build these
platform-tools and build-tools zips.

Bug: 187222815
Change-Id: I55809e1d7447dd65e22461f921b2b8abb6d5f822
diff --git a/android_sdk/Android.bp b/android_sdk/Android.bp
new file mode 100644
index 0000000..e686d59
--- /dev/null
+++ b/android_sdk/Android.bp
@@ -0,0 +1,22 @@
+package {
+    default_applicable_licenses: ["Android-Apache-2.0"],
+}
+
+bootstrap_go_package {
+    name: "soong-android-sdk",
+    pkgPath: "android/soong/android_sdk",
+    deps: [
+        "blueprint",
+        "soong",
+        "soong-android",
+        "soong-cc",
+        "soong-cc-config",
+    ],
+    srcs: [
+        "sdk_repo_host.go",
+    ],
+    testSrcs: [
+        "sdk_repo_host_test.go",
+    ],
+    pluginFor: ["soong_build"],
+}