respect relative_install_path for binaries in APEXes

Bug: 123721777
Test: m (apex_test.go has the test)
Change-Id: I89bc83d4bc6fe8dc374cf36e06e795c75b290844
diff --git a/apex/apex.go b/apex/apex.go
index 341968b..a70a37b 100644
--- a/apex/apex.go
+++ b/apex/apex.go
@@ -613,9 +613,7 @@
 }
 
 func getCopyManifestForExecutable(cc *cc.Module) (fileToCopy android.Path, dirInApex string) {
-	// TODO(b/123721777) respect relative_install_path also for binaries
-	// dirInApex = filepath.Join("bin", cc.RelativeInstallPath())
-	dirInApex = "bin"
+	dirInApex = filepath.Join("bin", cc.RelativeInstallPath())
 	fileToCopy = cc.OutputFile().Path()
 	return
 }