Bug 1406631: Make input[type=color] rules consistent on Android. r=xidorn

Before this patch, the :-moz-system-metric pseudo-class made the
input[type="color"] rules more specific than this rule in content.css:

  * > input:not(:-moz-any([type="image"], [type="checkbox"], [type="radio"]))

After removing it, this is not the case. This seems like an accident, so let's
make input[type="color"] consistent with the rest of the buttons just the same
way as in forms.css.

MozReview-Commit-ID: 7oPsxMBDdED

--HG--
extra : rebase_source : d75361515df9f3f2d9099c98274c587869fa9914

mobile/android/themes/geckoview/content.css

@@ -167,6 +167,7 @@ textarea {
 input[type="button"],
 input[type="submit"],
 input[type="reset"],
+input[type="color"],
 button {
   border-width: 1px;
   padding-inline-start: 7px;
@@ -206,6 +207,7 @@ input[type="file"]:focus > input[type="text"],
 select:not([size]):not([multiple]):focus,
 select[size="0"]:focus,
 select[size="1"]:focus,
+input[type="color"]:focus,
 input[type="button"]:focus,
 input[type="submit"]:focus,
 input[type="reset"]:focus,
@@ -247,6 +249,8 @@ input[type="submit"]:disabled,
 input[type="submit"]:disabled:active,
 input[type="reset"]:disabled,
 input[type="reset"]:disabled:active,
+input[type="color"]:disabled,
+input[type="color"]:disabled:active,
 button:disabled,
 button:disabled:active {
   padding-inline-start: 7px;