Bug 1880223 - Set auto min-height in textareas and fix heading sizing in connection settings r=desktop-theme-reviewers,settings-reviewers,emilio

This fixes an existing scrollbar issue pointed out on this patch's bug that became more predominant with some of the heading standardization work in bug 1877793.

I'm making sure the heading looks like how it used to. I also noticed textareas had a very small min-height that seemed to be causing this issue.

Differential Revision: https://phabricator.services.mozilla.com/D202018

browser/components/preferences/dialogs/colors.xhtml

@@ -41,7 +41,11 @@
 
     <hbox>
       <groupbox flex="1">
-        <label><html:h2 data-l10n-id="colors-text-and-background" /></label>
+        <label
+          ><html:h2
+            class="heading-medium"
+            data-l10n-id="colors-text-and-background"
+        /></label>
         <hbox align="center">
           <label
             data-l10n-id="colors-text-header"
@@ -74,7 +78,9 @@
       </groupbox>
 
       <groupbox flex="1">
-        <label><html:h2 data-l10n-id="colors-links-header" /></label>
+        <label
+          ><html:h2 class="heading-medium" data-l10n-id="colors-links-header"
+        /></label>
         <hbox align="center">
           <label
             data-l10n-id="colors-unvisited-links"

browser/components/preferences/dialogs/connection.xhtml

@@ -63,7 +63,11 @@
     </hbox>
 
     <groupbox>
-      <label><html:h2 data-l10n-id="connection-proxy-configure" /></label>
+      <label
+        ><html:h2
+          class="heading-medium"
+          data-l10n-id="connection-proxy-configure"
+      /></label>
 
       <radiogroup id="networkProxyType" preference="network.proxy.type">
         <radio value="0" data-l10n-id="connection-proxy-option-no" />

browser/components/preferences/dialogs/fonts.xhtml

@@ -43,7 +43,9 @@
     <groupbox>
       <hbox align="center">
         <label control="selectLangs"
-          ><html:h2 data-l10n-id="fonts-langgroup-header"
+          ><html:h2
+            class="heading-medium"
+            data-l10n-id="fonts-langgroup-header"
         /></label>
       </hbox>
       <menulist id="selectLangs" preference="font.language.group">

toolkit/themes/shared/in-content/common-shared.css

@@ -620,6 +620,10 @@ html|textarea {
   min-height: var(--input-text-min-height);
 }
 
+html|textarea {
+  min-height: auto
+}
+
 html|input:where([type="email"], [type="tel"], [type="text"], [type="password"], [type="url"], [type="number"]):focus,
 html|textarea:focus,
 xul|search-textbox[focused],