Bug 1919705 - Port bug 1919262: Remove --button-color. r=mkmelin

Differential Revision: https://phabricator.services.mozilla.com/D222746

--HG--
extra : moz-landing-system : lando

mail/themes/shared/mail/panelUI.css

@@ -735,7 +735,7 @@ toolbarpaletteitem[place="menu-panel"] > .subviewbutton-nav::after {
   padding-inline: 8px;
   padding-block: calc(var(--appmenu-button-padding) + 3px);
   border-radius: var(--arrowpanel-menuitem-border-radius);
-  color: var(--button-color);
+  color: var(--button-text-color);
   background-color: color-mix(in srgb, currentColor 7%, transparent);;
   margin-bottom: 4px;
   font-weight: 600;
@@ -1016,7 +1016,7 @@ menulist {
   height: var(--appmenu-fontsize-icon-size);
   -moz-context-properties: fill, stroke;
   fill: var(--button-background-color, ButtonFace);
-  stroke: var(--button-color);
+  stroke: var(--button-text-color);
   border-radius: 50%;
   margin-block-start: 1px;
   padding: 0;

mail/themes/shared/mail/popupPanel.css

@@ -156,7 +156,7 @@ html|input.editContactTextbox {
     appearance: none;
     border: 0;
     border-radius: 4px;
-    color: var(--button-color, inherit);
+    color: var(--button-text-color, inherit);
     background-color: var(--button-background-color, color-mix(in srgb, currentColor 13%, transparent));
     padding: 8px 16px;
     font-weight: 600;

mail/themes/shared/mail/variables.css

@@ -174,7 +174,7 @@
 
 @media (prefers-contrast) {
   :root:not([lwtheme]) {
-    --button-color: ButtonText;
+    --button-text-color: ButtonText;
     --button-background-color: ButtonFace;
     --button-border-color: ButtonText;
     --button-hover-text-color: SelectedItemText;