Make apex.key and certificate overridable.

Test: apex_test.go
Fixes: 185477325
Change-Id: I8992ac5606fa92f53f07e6870a034f2d3352e618
diff --git a/apex/apex_test.go b/apex/apex_test.go
index 977a954..a7ae6f0 100644
--- a/apex/apex_test.go
+++ b/apex/apex_test.go
@@ -5599,6 +5599,8 @@
 			overrides: ["unknownapex"],
 			logging_parent: "com.foo.bar",
 			package_name: "test.overridden.package",
+			key: "mynewapex.key",
+			certificate: ":myapex.certificate",
 		}
 
 		apex_key {
@@ -5607,6 +5609,17 @@
 			private_key: "testkey.pem",
 		}
 
+		apex_key {
+			name: "mynewapex.key",
+			public_key: "testkey2.avbpubkey",
+			private_key: "testkey2.pem",
+		}
+
+		android_app_certificate {
+			name: "myapex.certificate",
+			certificate: "testkey",
+		}
+
 		android_app {
 			name: "app",
 			srcs: ["foo/bar/MyClass.java"],
@@ -5651,6 +5664,10 @@
 
 	optFlags := apexRule.Args["opt_flags"]
 	ensureContains(t, optFlags, "--override_apk_package_name test.overridden.package")
+	ensureContains(t, optFlags, "--pubkey testkey2.avbpubkey")
+
+	signApkRule := module.Rule("signapk")
+	ensureEquals(t, signApkRule.Args["certificates"], "testkey.x509.pem testkey.pk8")
 
 	data := android.AndroidMkDataForTest(t, ctx, apexBundle)
 	var builder strings.Builder