build: ts-api-guardian should support interface with value types (#27223)

This fixes an issue where a value would hide the type.

```
export interface Foo {
  someMethod(): void;
}

export const Foo: Function = ...;
```

In the above example the `Foo` constant will hide the `interface Foo` symbol.
This change properly saves the interface in addition to the type.

PR Close #27223

packages/core/testing/src/test_bed.ts

@@ -20,6 +20,9 @@ const UNDEFINED = new Object();
 
 let _nextRootElementId = 0;
 
+/**
+ * @publicApi
+ */
 export interface TestBed {
   platform: PlatformRef;
 
@@ -35,16 +38,12 @@ export interface TestBed {
    *
    * Test modules and platforms for individual platforms are available from
    * '@angular/<platform_name>/testing'.
-   *
-   * @publicApi
    */
   initTestEnvironment(
       ngModule: Type<any>|Type<any>[], platform: PlatformRef, aotSummaries?: () => any[]): void;
 
   /**
    * Reset the providers for the test injector.
-   *
-   * @publicApi
    */
   resetTestEnvironment(): void;
 
@@ -119,8 +118,6 @@ export class TestBedViewEngine implements Injector, TestBed {
    *
    * Test modules and platforms for individual platforms are available from
    * '@angular/<platform_name>/testing'.
-   *
-   * @publicApi
    */
   static initTestEnvironment(
       ngModule: Type<any>|Type<any>[], platform: PlatformRef,
@@ -132,8 +129,6 @@ export class TestBedViewEngine implements Injector, TestBed {
 
   /**
    * Reset the providers for the test injector.
-   *
-   * @publicApi
    */
   static resetTestEnvironment(): void { _getTestBedViewEngine().resetTestEnvironment(); }
 
@@ -291,8 +286,6 @@ export class TestBedViewEngine implements Injector, TestBed {
    *
    * Test modules and platforms for individual platforms are available from
    * '@angular/<platform_name>/testing'.
-   *
-   * @publicApi
    */
   initTestEnvironment(
       ngModule: Type<any>|Type<any>[], platform: PlatformRef, aotSummaries?: () => any[]): void {
@@ -308,8 +301,6 @@ export class TestBedViewEngine implements Injector, TestBed {
 
   /**
    * Reset the providers for the test injector.
-   *
-   * @publicApi
    */
   resetTestEnvironment(): void {
     this.resetTestingModule();