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

java/java.go

@@ -565,10 +565,6 @@ func (j *Library) GenerateAndroidBuildActions(ctx android.ModuleContext) {
 		j.installFile = ctx.InstallFile(android.PathForModuleInstall(ctx, "framework"),
 			j.Stem()+".jar", j.outputFile, extraInstallDeps...)
 	}
-
-	if ctx.Windows() {
-		j.HideFromMake()
-	}
 }
 
 func (j *Library) DepsMutator(ctx android.BottomUpMutatorContext) {
@@ -1135,10 +1131,6 @@ func (j *Binary) GenerateAndroidBuildActions(ctx android.ModuleContext) {
 		j.binaryFile = ctx.InstallExecutable(android.PathForModuleInstall(ctx, "bin"),
 			ctx.ModuleName()+ext, j.wrapperFile)
 	}
-
-	if ctx.Windows() {
-		j.HideFromMake()
-	}
 }
 
 func (j *Binary) DepsMutator(ctx android.BottomUpMutatorContext) {