streams: Set width of select elements in stream settings page.

This commit sets width of select elements in stream settings
page to "auto" such that the width adjusts to fit the options
as required in different languages and we also keep minimum
width of 325px to maintain consistency of width across elements
in the page to not look ugly.

web/styles/subscriptions.css

@@ -982,8 +982,9 @@ div.settings-radio-input-parent {
     }
 
     .settings_select {
-        /* Match .setting_desktop_icon_count_display */
-        width: 325px;
+        /* Match with select elements in settings page */
+        min-width: 325px;
+        max-width: 100%;
         height: fit-content;
     }