MDL-56910 filepicker: give button BS styling

lib/outputrenderers.php

@@ -2594,7 +2594,7 @@ $icon_progress
 </div>
 <div id="filepicker-wrapper-{$client_id}" class="mdl-left" style="display:none">
     <div>
-        <input type="button" class="fp-btn-choose" id="filepicker-button-{$client_id}" value="{$straddfile}"{$buttonname}/>
+        <input type="button" class="btn btn-secondary fp-btn-choose" id="filepicker-button-{$client_id}" value="{$straddfile}"{$buttonname}/>
         <span> $maxsize </span>
     </div>
 EOD;

theme/boost/scss/moodle/buttons.scss

@@ -47,12 +47,6 @@ p.arrow_button {
     margin: 0 0 10px 5px;
 }
 
-input {
-    &.fp-btn-choose {
-        @extend .btn-sm;
-    }
-}
-
 .user-enroller-panel {
     .uep-search-results {
         .user,

theme/boost/scss/moodle/filemanager.scss

@@ -603,10 +603,6 @@ a.ygtvspacer:hover {
     background-color: #ebebe4;
 }
 
-.fitem.disabled .fp-btn-choose {
-    @extend .text-muted;
-}
-
 .fitem.disabled .filepicker-filelist .filepicker-filename {
     display: none;
 }

theme/bootstrapbase/less/moodle/buttons.less

@@ -113,12 +113,6 @@ button {
     }
 }
 
-input {
-    &.fp-btn-choose {
-        .btn-small
-    }
-}
-
 .user-enroller-panel {
     .uep-search-results {
         .user,

theme/bootstrapbase/less/moodle/filemanager.less

@@ -800,9 +800,6 @@ a.ygtvspacer:hover {
 .fitem.disabled .filemanager-container {
     background-color: #ebebe4;
 }
-.fitem.disabled .fp-btn-choose {
-    .muted
-}
 .fitem.disabled .filepicker-filelist .filepicker-filename {
     display: none;
 }