Use one mutator for all bp2build conversion.

Each conversion required defining a separate mutator, which will each
operate on _all_ modules and requires each to repeat checks whether the
mutator should operator. Instead, we introduce a single mutator and
modules can define a ConvertWithBp2build to implement bp2build
conversion for that module.

Test: bp2build.sh
Bug: 183079158
Change-Id: I99d4b51f441c2903879092c5b56313d606d4338d
diff --git a/bp2build/android_app_conversion_test.go b/bp2build/android_app_conversion_test.go
index b12b567..153817b 100644
--- a/bp2build/android_app_conversion_test.go
+++ b/bp2build/android_app_conversion_test.go
@@ -31,10 +31,9 @@
 
 func TestMinimalAndroidApp(t *testing.T) {
 	runAndroidAppTestCase(t, bp2buildTestCase{
-		description:                        "Android app - simple example",
-		moduleTypeUnderTest:                "android_app",
-		moduleTypeUnderTestFactory:         java.AndroidAppFactory,
-		moduleTypeUnderTestBp2BuildMutator: java.AppBp2Build,
+		description:                "Android app - simple example",
+		moduleTypeUnderTest:        "android_app",
+		moduleTypeUnderTestFactory: java.AndroidAppFactory,
 		filesystem: map[string]string{
 			"app.java":            "",
 			"res/res.png":         "",
@@ -58,10 +57,9 @@
 
 func TestAndroidAppAllSupportedFields(t *testing.T) {
 	runAndroidAppTestCase(t, bp2buildTestCase{
-		description:                        "Android app - all supported fields",
-		moduleTypeUnderTest:                "android_app",
-		moduleTypeUnderTestFactory:         java.AndroidAppFactory,
-		moduleTypeUnderTestBp2BuildMutator: java.AppBp2Build,
+		description:                "Android app - all supported fields",
+		moduleTypeUnderTest:        "android_app",
+		moduleTypeUnderTestFactory: java.AndroidAppFactory,
 		filesystem: map[string]string{
 			"app.java":                     "",
 			"resa/res.png":                 "",