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/dexpreopt_bootjars_test.go

@@ -84,6 +84,7 @@ func testDexpreoptBoot(t *testing.T, ruleFile string, expectedInputs, expectedOu
 }
 
 func TestDexpreoptBootJars(t *testing.T) {
+	t.Parallel()
 	ruleFile := "boot-foo.art"
 
 	expectedInputs := []string{
@@ -114,6 +115,7 @@ func TestDexpreoptBootJars(t *testing.T) {
 
 // Changes to the boot.zip structure may break the ART APK scanner.
 func TestDexpreoptBootZip(t *testing.T) {
+	t.Parallel()
 	ruleFile := "boot.zip"
 
 	ctx := android.PathContextForTesting(testConfig(nil, "", nil))