avoid changing specificity of old selectors

Author: kseamon

src/material-experimental/mdc-form-field/_form-field-subscript.scss

@@ -16,25 +16,30 @@
 
   .mat-mdc-form-field-hint-wrapper,
   .mat-mdc-form-field-error-wrapper {
+    position: absolute;
+    top: 0;
+    left: 0;
+    right: 0;
     padding: 0 mdc-textfield-variables.$padding-horizontal;
   }
 
-  .mat-mdc-form-field-bottom-align:not(.mat-mdc-form-field-subscript-dynamic-size) {
+  .mat-mdc-form-field-subscript-dynamic-size {
     .mat-mdc-form-field-hint-wrapper,
     .mat-mdc-form-field-error-wrapper {
-      position: absolute;
-      top: 0;
-      left: 0;
-      right: 0;
+      position: static;
     }
   }
 
-  .mat-mdc-form-field-bottom-align:not(.mat-mdc-form-field-subscript-dynamic-size)::before {
+  .mat-mdc-form-field-bottom-align::before {
     content: '';
     display: inline-block;
     height: 16px;
   }
 
+  .mat-mdc-form-field-bottom-align.mat-mdc-form-field-subscript-dynamic-size::before {
+    content: unset;
+  }
+
   .mat-mdc-form-field-hint-end {
     order: 1;
   }