Protect the Swupd_Root.pem certificate file

This test creates an alternate swupd root certificate. If one already
exists, back it up, and restore it when the test is done. Previously,
this test just blindly deleted the certificate if it existed.

test/functional/only_in_ci_system/api-3rd-party-add.bats

@@ -5,6 +5,8 @@
 
 load "../testlib"
 
+SWUPD_ROOT_CERT=/usr/share/clear/update-ca/Swupd_Root.pem
+
 test_setup() {
 
 	# Skip this test for local development because we write the certificate on /
@@ -16,9 +18,11 @@ test_setup() {
 
 	create_test_environment "$TEST_NAME"
 
-	sudo rm -f /usr/share/clear/update-ca/Swupd_Root.pem
+	# Backup the original certificate
+	[[ -f ${SWUPD_ROOT_CERT} ]] &&
+		mv ${SWUPD_ROOT_CERT} ${SWUPD_ROOT_CERT}.orig
 	sudo mkdir -p /usr/share/clear/update-ca
-	sudo cp test/functional/only_in_ci_system/pemfile /usr/share/clear/update-ca/Swupd_Root.pem
+	sudo cp test/functional/only_in_ci_system/pemfile ${SWUPD_ROOT_CERT}
 
 	create_third_party_repo "$TEST_NAME" 10 staging repo1
 	export repo1="$ABS_TP_URL"
@@ -31,7 +35,10 @@ test_teardown() {
 		return
 	fi
 
-	sudo rm -f /usr/share/clear/update-ca/Swupd_Root.pem
+	sudo rm -f ${SWUPD_ROOT_CERT}
+	# Restore the original certificate
+	[[ -f ${SWUPD_ROOT_CERT}.orig ]] &&
+		mv ${SWUPD_ROOT_CERT}.orig ${SWUPD_ROOT_CERT}
 
 }