fix(iOS): active app under test on XCUITest interaction.

[asafkorem]

This update ensures the app-under-test remains active and prevents device locks during each launch of the XCUITest runner process.

/*!
 * Activates the application synchronously. On return the application is ready to handle events.
 * If the application was not running prior, it will be launched automatically. If the application
 * would be launched as a result of this method and was previously launched via -launch, the launch
 * arguments and environment variables that were used then will be supplied again for the new launch.
 *
 * Unlike -launch, if the application is already running this call will not terminate the existing
 * instance.
 *
 * Any failure in the activation or launch sequence will be reported as a test failure and the test
 * will be halted at that point.
*/
- (void)activate;