Use correct install paths in generated Android.mk

Extract Soong's install path and put it in the generated Android.mk file
so that tests get installed in the correct place.

Change-Id: Id4726855c5677855406de20773a5da533bdd4cea
diff --git a/common/androidmk.go b/common/androidmk.go
index 49380e0..a16a652 100644
--- a/common/androidmk.go
+++ b/common/androidmk.go
@@ -38,6 +38,7 @@
 
 type AndroidMkData struct {
 	Class      string
+	SubName    string
 	OutputFile OptionalPath
 	Disabled   bool
 
@@ -141,6 +142,10 @@
 		return err
 	}
 
+	if data.SubName != "" {
+		name += "_" + data.SubName
+	}
+
 	hostCross := false
 	if amod.Host() && amod.HostType() != CurrentHostType() {
 		hostCross = true