bios: Converting bios json keys to lower snake case

Converting following bios attribute json keys to lower snake case
displayName --> display_name
helpText    --> help_text
readOnly    --> read_only

Tested:
     Power on/off
     Gtest passed

Change-Id: Iad88ed7bc381d66182c99e31e7d385f65750e0ed
Signed-off-by: Archana Kakani <archana.kakani@ibm.com>
diff --git a/libpldmresponder/test/libpldmresponder_bios_enum_attribute_test.cpp b/libpldmresponder/test/libpldmresponder_bios_enum_attribute_test.cpp
index 775cd15..98161a0 100644
--- a/libpldmresponder/test/libpldmresponder_bios_enum_attribute_test.cpp
+++ b/libpldmresponder/test/libpldmresponder_bios_enum_attribute_test.cpp
@@ -39,9 +39,9 @@
          "possible_values" : [ "Concurrent", "Disruptive" ],
          "value_names" : [ "Concurrent", "Disruptive" ],
          "default_values" : [ "Concurrent" ],
-         "readOnly" : true,
-         "helpText" : "HelpText",
-         "displayName" : "DisplayName"
+         "read_only" : true,
+         "help_text" : "HelpText",
+         "display_name" : "DisplayName"
       })"_json;
 
     BIOSEnumAttribute enumReadOnly{jsonEnumReadOnly, nullptr};
@@ -56,9 +56,9 @@
          "possible_value" : [ "Concurrent", "Disruptive" ],
          "value_names" : [ "Concurrent", "Disruptive" ],
          "default_values" : [ "Concurrent" ],
-         "readOnly" : true,
-         "helpText" : "HelpText",
-         "displayName" : "DisplayName"
+         "read_only" : true,
+         "help_text" : "HelpText",
+         "display_name" : "DisplayName"
       })"_json; // possible_value -> possible_values
     EXPECT_THROW((BIOSEnumAttribute{jsonEnumReadOnlyError, nullptr}),
                  Json::exception);
@@ -68,9 +68,9 @@
          "possible_values" : [ "Perm", "Temp" ],
          "value_names" : [ "Perm", "Temp" ],
          "default_values" : [ "Perm" ],
-         "readOnly" : false,
-         "helpText" : "HelpText",
-         "displayName" : "DisplayName",
+         "read_only" : false,
+         "help_text" : "HelpText",
+         "display_name" : "DisplayName",
          "dbus":
             {
                "object_path" : "/xyz/abc/def",
@@ -96,9 +96,9 @@
          "possible_values" : [ "Concurrent", "Disruptive" ],
          "value_names" : [ "Concurrent", "Disruptive" ],
          "default_values" : [ "Disruptive" ],
-         "readOnly" : true,
-         "helpText" : "HelpText",
-         "displayName" : "DisplayName"
+         "read_only" : true,
+         "help_text" : "HelpText",
+         "display_name" : "DisplayName"
       })"_json;
 
     std::vector<uint8_t> expectedAttrEntry{
@@ -136,9 +136,9 @@
          "possible_values" : [ "Concurrent", "Disruptive" ],
          "value_names" : [ "Concurrent", "Disruptive" ],
          "default_values" : [ "Disruptive" ],
-         "readOnly" : false,
-         "helpText" : "HelpText",
-         "displayName" : "DisplayName",
+         "read_only" : false,
+         "help_text" : "HelpText",
+         "display_name" : "DisplayName",
          "dbus":
             {
                "object_path" : "/xyz/abc/def",
@@ -189,9 +189,9 @@
          "possible_values" : [ "Concurrent", "Disruptive" ],
          "value_names" : [ "Concurrent", "Disruptive" ],
          "default_values" : [ "Disruptive" ],
-         "readOnly" : false,
-         "helpText" : "HelpText",
-         "displayName" : "DisplayName",
+         "read_only" : false,
+         "help_text" : "HelpText",
+         "display_name" : "DisplayName",
          "dbus":
             {
                "object_path" : "/xyz/abc/def",