fix(popover-edit): incorrect spacing for form field inside popover

For some reason the padding on `mat-form-field` was reset inside the popover edit overlay which made it looked weird. From what I can tell, there's no reason to do this so these changes remove the override.

Author: crisbeto

src/material-experimental/popover-edit/_popover-edit.scss

@@ -100,14 +100,9 @@
   }
 
   [mat-edit-content] {
-    display: block;
-
-    mat-form-field {
+    &,
+    & mat-form-field {
       display: block;
-
-      &:not(.mat-form-field-has-label) .mat-form-field-infix {
-        padding: 0;
-      }
     }
   }