Fix TerraformProvider alias definition

packages/cdktf/lib/terraform-provider.ts

@@ -14,7 +14,6 @@ export abstract class TerraformProvider extends TerraformElement {
   public readonly terraformResourceType: string;
   public readonly terraformGeneratorMetadata?: TerraformGeneratorMetadata;
   public readonly terraformProviderSource?: string;
-  public alias?: string;
 
   constructor(scope: Construct, id: string, config: TerraformProviderConfig) {
     super(scope, id);
@@ -24,6 +23,15 @@ export abstract class TerraformProvider extends TerraformElement {
     this.terraformProviderSource = config.terraformProviderSource;
   }
 
+  public get alias(): string | undefined {
+    // This is always* being overriden currently
+    return undefined;
+  }
+
+  public set alias(_value: string | undefined) {
+    // This is always* being overriden currently
+  }
+
   public get fqn(): string {
     return (this.alias !== undefined) ? Token.asString(`${this.terraformResourceType}.${this.alias}`) : Token.asString(`${this.terraformResourceType}`);
   }

packages/cdktf/test/helper/provider.ts

@@ -11,7 +11,6 @@ export enum TestProviderMetadata {
 }
 
 export class TestProvider extends TerraformProvider {
-  public alias?: string;
   public accessKey: string;
 
   constructor(scope: Construct, id: string, config: TestProviderConfig) {
@@ -23,6 +22,14 @@ export class TestProvider extends TerraformProvider {
     this.accessKey = config.accessKey
   }
 
+  private _alias?: string;
+  public get alias() {
+    return this._alias;
+  }
+  public set alias(value: string | undefined) {
+    this._alias = value;
+  }
+
   protected synthesizeAttributes(): { [name: string]: any } {
     return {
       // eslint-disable-next-line @typescript-eslint/camelcase