Revert "Make lots of tests run in parallel"

This reverts commit 323dc60712.

Reason for revert: Possible cause of test instability
Bug: 170513220
Test: soong tests

Change-Id: Iee168e9fbb4210569e6cffcc23e60d111403abb8

java/device_host_converter_test.go

@@ -22,7 +22,6 @@ import (
 )
 
 func TestDeviceForHost(t *testing.T) {
-	t.Parallel()
 	bp := `
 		java_library {
 			name: "device_module",
@@ -103,7 +102,6 @@ func TestDeviceForHost(t *testing.T) {
 }
 
 func TestHostForDevice(t *testing.T) {
-	t.Parallel()
 	bp := `
 		java_library_host {
 			name: "host_module",