[ts] Upgrade to TypeScript 3.9.2 (expo#8280)

* [ts] Upgrade to TypeScript 3.9.2

This upgrades TypeScript to 3.9.2 to keep us more up to date. It also supports `@ts-expect-error` for places where we want to get notified if a future TS version stops triggering type checker errors. https://devblogs.microsoft.com/typescript/announcing-typescript-3-9/

It is also supposed to be faster but I don't have real numbers on this. CI might be a reasonable indicator.

Also updated ts-jest, since there was a bug that required clearing the Jest cache.

Updated the TS version in expo-module-scripts. Ran `expotools check-packages --no-uniformity-check ` to rebuild, test, and lint all files.

* [ts] Fix up files for TS 3.9

* [ts] Rebuild JS files with TS 3.9.2

build/AV.d.ts

@@ -97,14 +97,14 @@ export interface Playback extends AV {
 export declare const PlaybackMixin: {
     playAsync(): Promise<AVPlaybackStatus>;
     playFromPositionAsync(positionMillis: number, tolerances?: {
-        toleranceMillisBefore?: number | undefined;
-        toleranceMillisAfter?: number | undefined;
+        toleranceMillisBefore?: number;
+        toleranceMillisAfter?: number;
     }): Promise<AVPlaybackStatus>;
     pauseAsync(): Promise<AVPlaybackStatus>;
     stopAsync(): Promise<AVPlaybackStatus>;
     setPositionAsync(positionMillis: number, tolerances?: {
-        toleranceMillisBefore?: number | undefined;
-        toleranceMillisAfter?: number | undefined;
+        toleranceMillisBefore?: number;
+        toleranceMillisAfter?: number;
     }): Promise<AVPlaybackStatus>;
     setRateAsync(rate: number, shouldCorrectPitch?: boolean, pitchCorrectionQuality?: PitchCorrectionQuality): Promise<AVPlaybackStatus>;
     setVolumeAsync(volume: number): Promise<AVPlaybackStatus>;