test/manifest/image-installer: fix conflicting merge

The new image-installer tests were merged at the same time as the isolevel support. Adjust the test cases.

test/data/manifests/centos_8-aarch64-image_installer-boot.json

@@ -2062,7 +2062,8 @@
               "filename": "installer.iso",
               "volid": "CentOS-Stream-8-aarch64-dvd",
               "sysid": "LINUX",
-              "efi": "images/efiboot.img"
+              "efi": "images/efiboot.img",
+              "isolevel": 3
             }
           },
           {
@@ -21914,4 +21915,4 @@
       }
     ]
   }
-}
+}

test/data/manifests/centos_9-aarch64-image_installer-boot.json

@@ -2018,7 +2018,8 @@
               "filename": "installer.iso",
               "volid": "CentOS-Stream-9-BaseOS-aarch64",
               "sysid": "LINUX",
-              "efi": "images/efiboot.img"
+              "efi": "images/efiboot.img",
+              "isolevel": 3
             }
           },
           {
@@ -21514,4 +21515,4 @@
       }
     ]
   }
-}
+}

test/data/manifests/rhel_86-aarch64-image_installer-boot.json

@@ -2093,7 +2093,8 @@
               "filename": "installer.iso",
               "volid": "RHEL-8-6-0-BaseOS-aarch64",
               "sysid": "LINUX",
-              "efi": "images/efiboot.img"
+              "efi": "images/efiboot.img",
+              "isolevel": 3
             }
           },
           {
@@ -20563,4 +20564,4 @@
       }
     ]
   }
-}
+}

test/data/manifests/rhel_90-aarch64-image_installer-boot.json

@@ -2041,7 +2041,8 @@
               "filename": "installer.iso",
               "volid": "RHEL-9-0-0-BaseOS-aarch64",
               "sysid": "LINUX",
-              "efi": "images/efiboot.img"
+              "efi": "images/efiboot.img",
+              "isolevel": 3
             }
           },
           {
@@ -20127,4 +20128,4 @@
       }
     ]
   }
-}
+}