feat: Add onStarted and onStopped events (#2273)

* feat: Add `onStarted` and `onStopped` events

* Implement `onStart` for Android

* Update CameraSession.kt

* Update CameraSessionDelegate.swift

package/src/Camera.tsx

@@ -33,6 +33,8 @@ type NativeCameraViewProps = Omit<CameraProps, 'device' | 'onInitialized' | 'onE
   onInitialized?: (event: NativeSyntheticEvent<void>) => void
   onError?: (event: NativeSyntheticEvent<OnErrorEvent>) => void
   onCodeScanned?: (event: NativeSyntheticEvent<OnCodeScannedEvent>) => void
+  onStarted?: (event: NativeSyntheticEvent<void>) => void
+  onStopped?: (event: NativeSyntheticEvent<void>) => void
   onViewReady: () => void
 }
 type NativeRecordVideoOptions = Omit<RecordVideoOptions, 'onRecordingError' | 'onRecordingFinished' | 'videoBitRate'> & {
@@ -89,6 +91,8 @@ export class Camera extends React.PureComponent<CameraProps, CameraState> {
     super(props)
     this.onViewReady = this.onViewReady.bind(this)
     this.onInitialized = this.onInitialized.bind(this)
+    this.onStarted = this.onStarted.bind(this)
+    this.onStopped = this.onStopped.bind(this)
     this.onError = this.onError.bind(this)
     this.onCodeScanned = this.onCodeScanned.bind(this)
     this.ref = React.createRef<RefType>()
@@ -416,6 +420,14 @@ export class Camera extends React.PureComponent<CameraProps, CameraState> {
   private onInitialized(): void {
     this.props.onInitialized?.()
   }
+
+  private onStarted(): void {
+    this.props.onStarted?.()
+  }
+
+  private onStopped(): void {
+    this.props.onStopped?.()
+  }
   //#endregion
 
   private onCodeScanned(event: NativeSyntheticEvent<OnCodeScannedEvent>): void {
@@ -481,6 +493,8 @@ export class Camera extends React.PureComponent<CameraProps, CameraState> {
         onViewReady={this.onViewReady}
         onInitialized={this.onInitialized}
         onCodeScanned={this.onCodeScanned}
+        onStarted={this.onStarted}
+        onStopped={this.onStopped}
         onError={this.onError}
         codeScannerOptions={codeScanner}
         enableFrameProcessor={frameProcessor != null}

package/src/CameraProps.ts

@@ -246,9 +246,17 @@ export interface CameraProps extends ViewProps {
    */
   onError?: (error: CameraRuntimeError) => void
   /**
-   * Called when the camera was successfully initialized.
+   * Called when the camera session was successfully initialized. This will get called everytime a new device is set.
    */
   onInitialized?: () => void
+  /**
+   * Called when the camera started the session (`isActive={true}`)
+   */
+  onStarted?: () => void
+  /**
+   * Called when the camera stopped the session (`isActive={false}`)
+   */
+  onStopped?: () => void
   /**
    * A worklet which will be called for every frame the Camera "sees".
    *