For anyone else facing the same issue. This is the syntax:
[/Script/AndroidRuntimeSettings.AndroidRuntimeSettings]
+ObbFilters="-*pakchunk1*"
+ObbFilters="-*pakchunk2*"
+ObbFilters="-*pakchunk3*"
+ObbFilters="-*pakchunk4*"
+ObbFilters="-*pakchunk5*"
+ObbFilters="-*pakchunk6*"
+ObbFilters="-*pakchunk7*"
+ObbFilters="-*pakchunk8*"
+ObbFilters="-*pakchunk9*"