Allow platform_bootclasspath to specify contributing fragments

Adds the fragments property to the platform_bootclasspath to allow the
fragments that contribute to it to be specified.

Bug: 177892522
Test: m nothing
Change-Id: I14f83d9336f6984442c7315cc86dfdd0a0fd2d20
diff --git a/apex/platform_bootclasspath_test.go b/apex/platform_bootclasspath_test.go
index 4aed9e0..2ea6401 100644
--- a/apex/platform_bootclasspath_test.go
+++ b/apex/platform_bootclasspath_test.go
@@ -127,10 +127,28 @@
 
 		platform_bootclasspath {
 			name: "myplatform-bootclasspath",
+
+			fragments: [
+				{
+					apex: "com.android.art",
+					module: "art-bootclasspath-fragment",
+				},
+			],
 		}
 `,
 	)
 
+	java.CheckPlatformBootclasspathModules(t, result, "myplatform-bootclasspath", []string{
+		"com.android.art:baz",
+		"com.android.art:quuz",
+		"platform:foo",
+		"myapex:bar",
+	})
+
+	java.CheckPlatformBootclasspathFragments(t, result, "myplatform-bootclasspath", []string{
+		`com.android.art:art-bootclasspath-fragment`,
+	})
+
 	// Make sure that the myplatform-bootclasspath has the correct dependencies.
 	CheckModuleDependencies(t, result.TestContext, "myplatform-bootclasspath", "android_common", []string{
 		`platform:dex2oatd`,
@@ -138,6 +156,7 @@
 		`com.android.art:quuz`,
 		`platform:foo`,
 		`myapex:bar`,
+		`com.android.art:art-bootclasspath-fragment`,
 	})
 }