Add phony name for robolectric tests

Robolectric tests are installed by Soong, which means Make doesn't
know about the install location to create the phony rules.  Add
a phony rule in Soong for now until Soong's installation rules are
fleshed out.

Bug: 184946827
Test: m SettingsRoboTests
Change-Id: I60d76474949800e1a737714d86df84eff9a92214
diff --git a/java/robolectric.go b/java/robolectric.go
index a0c9c7f..35239f8 100644
--- a/java/robolectric.go
+++ b/java/robolectric.go
@@ -212,7 +212,13 @@
 		installDeps = append(installDeps, installedData)
 	}
 
-	ctx.InstallFile(installPath, ctx.ModuleName()+".jar", r.combinedJar, installDeps...)
+	installed := ctx.InstallFile(installPath, ctx.ModuleName()+".jar", r.combinedJar, installDeps...)
+
+	if r.ExportedToMake() {
+		// Soong handles installation here, but Make is usually what creates the phony rule that atest
+		// uses to build the module.  Create it here for now.
+		ctx.Phony(ctx.ModuleName(), installed)
+	}
 }
 
 func generateRoboTestConfig(ctx android.ModuleContext, outputFile android.WritablePath,