CPT: Fatal error when using Front End Editor

[kraftbj]

When using the Front End Editor feature plugin, a fatal is thrown due to us assuming the enter_title_here filter will only run within wp-admin

Fatal error: Uncaught Error: Call to undefined function get_current_screen() in
/public_html/wp-content/plugins/jetpack-dev/modules/custom-post-types/testimonial.php:371
Stack trace: #0
/public_html/wp-includes/class-wp-hook.php(288):
Jetpack_Testimonial->change_default_title('Enter title her...') #1
/public_html/wp-includes/plugin.php(203):
WP_Hook->apply_filters('Enter title her...', Array) #2
/public_html/wp-content/plugins/wp-front-end-editor/class-fee.php(242):
apply_filters('enter_title_her...', 'Enter title her...', Object(WP_Post)) #3
public_html/wp-includes/class-wp-hook.php(286):
FEE->register_scripts('') #4
public_html/wp-includes/class-wp-hook.php(310):
WP_Hook->apply_filters(NULL, Array) #5
public_html/wp-includes/plugin.php(453):
WP_Hook->do_action(Array) #6 in
public_html/wp-content/plugins/jetpack-dev/modules/custom-post-types/testimonial.php
on line 371

Reported by beta tester in 722002-zen