Add ability to set --rotation-min-sdk-version for signapk via Android.bp files.

(vs via Android.mk files, done earlier in http://ag/16094391)

Bug: 197787352

Test: Added unit tests.

Change-Id: I3ccd2f2134b069fb4c4a90fe384c23c1814c2ba2
diff --git a/java/app_import_test.go b/java/app_import_test.go
index efa52c1..55d24c4 100644
--- a/java/app_import_test.go
+++ b/java/app_import_test.go
@@ -112,6 +112,7 @@
 			certificate: "platform",
 			additional_certificates: [":additional_certificate"],
 			lineage: "lineage.bin",
+			rotationMinSdkVersion: "32",
 		}
 
 		android_app_certificate {
@@ -131,11 +132,12 @@
 	if expected != certificatesFlag {
 		t.Errorf("Incorrect certificates flags, expected: %q, got: %q", expected, certificatesFlag)
 	}
-	// Check cert signing lineage flag.
-	signingFlag := signedApk.Args["flags"]
-	expected = "--lineage lineage.bin"
-	if expected != signingFlag {
-		t.Errorf("Incorrect signing flags, expected: %q, got: %q", expected, signingFlag)
+
+	// Check cert signing flags.
+	actualCertSigningFlags := signedApk.Args["flags"]
+	expectedCertSigningFlags := "--lineage lineage.bin --rotation-min-sdk-version 32"
+	if expectedCertSigningFlags != actualCertSigningFlags {
+		t.Errorf("Incorrect signing flags, expected: %q, got: %q", expectedCertSigningFlags, actualCertSigningFlags)
 	}
 }