Make lots of tests run in parallel

Putting t.Parallel() in each test makes them run in parallel.
Additional t.Parallel() could be added to each subtest, although
that requires making a local copy of the loop variable for
table driven tests.

Test: m checkbuild
Change-Id: I5d9869ead441093f4d7c5757f2447385333a95a4

java/kotlin_test.go

@@ -22,6 +22,7 @@ import (
 )
 
 func TestKotlin(t *testing.T) {
+	t.Parallel()
 	ctx, _ := testJava(t, `
 		java_library {
 			name: "foo",
@@ -84,6 +85,7 @@ func TestKotlin(t *testing.T) {
 }
 
 func TestKapt(t *testing.T) {
+	t.Parallel()
 	ctx, _ := testJava(t, `
 		java_library {
 			name: "foo",
@@ -163,6 +165,7 @@ func TestKapt(t *testing.T) {
 }
 
 func TestKaptEncodeFlags(t *testing.T) {
+	t.Parallel()
 	// Compares the kaptEncodeFlags against the results of the example implementation at
 	// https://kotlinlang.org/docs/reference/kapt.html#apjavac-options-encoding
 	tests := []struct {