[Ubuntu] Update maven to 3.8.4 (#4550)

Author: mikhailkoliada

images/linux/toolsets/toolset-1804.json

@@ -74,7 +74,7 @@
         "versions": [
             "8", "11", "12"
         ],
-        "maven": "3.8.3"
+        "maven": "3.8.4"
     },
     "android": {
         "platform_min_version": "23",

images/linux/toolsets/toolset-2004.json

@@ -75,7 +75,7 @@
         "versions": [
             "8", "11"
         ],
-        "maven": "3.8.3"
+        "maven": "3.8.4"
     },
     "android": {
         "platform_min_version": "27",