Fix lint and formatting issues

Author: jermowery

src/material/button/button.scss

@@ -135,9 +135,10 @@ $fallbacks: m3-button.get-tokens();
   }
 
   .mat-mdc-button-progress-indicator-container {
-    @include progress-spinner-theme.overrides((active-indicator-color: token-utils.slot(button-filled-progress-active-indicator-color,
-          $fallbacks ),
-      ));
+    @include progress-spinner-theme.overrides(
+      (active-indicator-color: token-utils.slot(
+        button-filled-progress-active-indicator-color, $fallbacks))
+    );
   }
 
   // We need to re-apply the disabled tokens since MDC uses
@@ -348,10 +349,9 @@ $fallbacks: m3-button.get-tokens();
 }
 
 .mat-mdc-button-progress-indicator-shown {
-  .material-icons,
   mat-icon,
   [matButtonIcon],
   .mdc-button__label {
     visibility: hidden;
   }
-}
+}

src/material/button/fab.scss

@@ -242,7 +242,6 @@ $fallbacks: m3-fab.get-tokens();
 }
 
 .mat-mdc-button-progress-indicator-shown {
-  .material-icons,
   mat-icon,
   [matButtonIcon],
   .mdc-button__label {

src/material/button/icon-button.scss

@@ -103,7 +103,6 @@ $fallbacks: m3-icon-button.get-tokens();
 }
 
 .mat-mdc-button-progress-indicator-shown {
-  .material-icons,
   mat-icon {
     visibility: hidden;
   }

src/material/button/testing/button-harness.ts

@@ -66,7 +66,7 @@ export class MatButtonHarness extends ContentContainerComponentHarness {
       });
   }
 
-  private readonly progressIndicator = this.locatorForOptional('[progressIndicator]');
+  private readonly _progressIndicator = this.locatorForOptional('[progressIndicator]');
 
   /**
    * Clicks the button at the given position relative to its top-left.
@@ -113,7 +113,7 @@ export class MatButtonHarness extends ContentContainerComponentHarness {
 
   /** Whether the button is showing a progress indicator. */
   async isShowingProgress(): Promise<boolean> {
-    return (await this.progressIndicator()) !== null;
+    return (await this._progressIndicator()) !== null;
   }
 
   /** Gets the variant of the button. */