MOBILE-3814 style: Add box shadow to fab and blocks buttons

src/core/features/block/components/side-blocks-button/side-blocks-button.scss

@@ -12,6 +12,7 @@
         --padding-end: 0;
         --border-radius: 2em 0 0 2em;
         height: 56px;
+        --box-shadow: 0 3px 5px -1px rgba(0, 0, 0, .2), 0 6px 10px 0 rgba(0, 0, 0, .14), 0 1px 18px 0 rgba(0, 0, 0, .12);
 
         &::part(native) {
             @include core-transition(padding, 200ms);

src/theme/theme.base.scss

@@ -298,6 +298,10 @@ button,
     min-width: var(--a11y-min-target-size);
 }
 
+ion-fab-button {
+    --box-shadow: 0 3px 5px -1px rgba(0, 0, 0, .2), 0 6px 10px 0 rgba(0, 0, 0, .14), 0 1px 18px 0 rgba(0, 0, 0, .12);
+}
+
 ion-button {
     margin: 4px 8px;