message: [core/api/app] Set FeatureFlags class to static
diff: @@ -21,9 +21,9 @@ import { FeatureFlagsApi } from '../apis/definitions/featureFlags';
  // TODO: figure out where to put implementations of APIs, both inside apps
  // but also in core/separate package.
  export class FeatureFlags implements FeatureFlagsApi {
  - private readonly localStorageKey = 'featureFlags';
  + private static readonly localStorageKey = 'featureFlags';
  - private getEnabledFeatureFlags(): Set<FeatureFlagName> {
  + private static getEnabledFeatureFlags(): Set<FeatureFlagName> {
  if (!('localStorage' in window)) {
  throw new Error(
  'Feature Flags are not supported on browsers without the Local Storage API',
  @@ -40,7 +40,7 @@ export class FeatureFlags implements FeatureFlagsApi {
  }
  }
  - private saveFeatureFlags(flags: Set<FeatureFlagName>): void {
  + private static saveFeatureFlags(flags: Set<FeatureFlagName>): void {
  if (!('localStorage' in window)) {
  throw new Error(
  'Feature Flags are not supported on browsers without the Local Storage API',
  @@ -55,17 +55,17 @@ export class FeatureFlags implements FeatureFlagsApi {
  );
  }
  - getItem(name: FeatureFlagName): boolean {
  + static getItem(name: FeatureFlagName): boolean {
  return this.getFeatureFlags().has(name);
  }
  - enable(name: FeatureFlagName): void {
  + static enable(name: FeatureFlagName): void {
  const flags = this.getFeatureFlags();
  flags.add(name);
  this.saveFeatureFlags(flags);
  }
  - disable(name: FeatureFlagName): void {
  + static disable(name: FeatureFlagName): void {
  const flags = this.getFeatureFlags();
  flags.delete(name);
  this.saveFeatureFlags(flags);
  