Do not explicitely define Exec line for KCM

See frameworks/kservice!16.

CCBUG: 398803

kcms/access/kcmaccess.desktop

 [Desktop Entry]
-Exec=kcmshell5 kcmaccess
 Icon=preferences-desktop-accessibility
 Type=Service
 X-KDE-ServiceTypes=KCModule

kcms/activities/kcm_activities.desktop

 [Desktop Entry]
-Exec=kcmshell5 activities
 Icon=preferences-desktop-activities
 Type=Service
 X-KDE-ServiceTypes=KCModule

kcms/autostart/package/metadata.desktop

@@ -142,7 +142,6 @@ Comment[zh_TW]=自動啟動應用程式
 Encoding=UTF-8
 Type=Service
 Icon=system-run
-Exec=kcmshell5 autostart
 X-KDE-Library=kcm_autostart
 X-KDE-ServiceTypes=KCModule
 X-KDE-FormFactors=desktop

kcms/baloo/kcm_baloofile.desktop

 [Desktop Entry]
-Exec=kcmshell5 kcm_baloofile
 Icon=preferences-desktop-baloo
 Type=Service
 

kcms/componentchooser/componentchooser.desktop

 [Desktop Entry]
-Exec=kcmshell5 componentchooser
 Icon=preferences-desktop-default-applications
 Type=Service
 X-KDE-ServiceTypes=KCModule

kcms/dateandtime/clock.desktop

 [Desktop Entry]
-Exec=kcmshell5 clock
 Icon=preferences-system-time
 Type=Service
 X-KDE-ServiceTypes=KCModule

kcms/desktoppaths/desktoppath.desktop

@@ -3,7 +3,6 @@ Type=Service
 X-KDE-ServiceTypes=KCModule
 X-DocPath=kcontrol/paths/index.html
 Icon=system-file-manager
-Exec=kcmshell5 desktoppath
 
 X-KDE-Library=kcm_desktoppaths
 X-KDE-ParentApp=kcontrol

kcms/formats/formats.desktop

 [Desktop Entry]
-Exec=kcmshell5 formats
 Icon=preferences-desktop-locale
 Type=Service
 X-KDE-ServiceTypes=KCModule

kcms/hardware/joystick/joystick.desktop

 [Desktop Entry]
-Exec=kcmshell5 joystick
-
 X-DocPath=kcontrol/joystick/index.html
 Terminal=false
 Type=Service

kcms/input/mouse.desktop

 [Desktop Entry]
-Exec=kcmshell5 mouse
 Icon=preferences-desktop-mouse
 Type=Service
 X-KDE-ServiceTypes=KCModule,KCModuleInit

kcms/kded/kcmkded.desktop

 [Desktop Entry]
-Exec=kcmshell5 kcmkded
 Icon=preferences-system-session-services
 Type=Service
 X-KDE-ServiceTypes=KCModule

kcms/keyboard/kcm_keyboard.desktop

 [Desktop Entry]
-Exec=kcmshell5 kcm_keyboard
 Icon=preferences-desktop-keyboard
 Type=Service
 X-KDE-ServiceTypes=KCModule

kcms/keys/kcm_keys.desktop

 [Desktop Entry]
-Exec=kcmshell5 kcm_keys
 Icon=preferences-desktop-keyboard-shortcut
 Type=Service
 X-KDE-ServiceTypes=KCModule

kcms/ksmserver/kcmsmserver.desktop

 [Desktop Entry]
-Exec=kcmshell5 kcmsmserver
 Icon=system-log-out
 Type=Service
 X-KDE-ServiceTypes=KCModule

kcms/ksplash/kcm_splashscreen.desktop

 [Desktop Entry]
 Icon=preferences-system-splash
-Exec=kcmshell5 kcm_splashscreen
 X-DocPath=kcontrol/splashscreen/index.html
 
 Type=Service

kcms/launch/kcm_launchfeedback.desktop

@@ -3,7 +3,6 @@ Icon=preferences-desktop-launch-feedback
 Type=Service
 X-KDE-ServiceTypes=KCModule
 X-DocPath=kcontrol/kcmlaunchfeedback/index.html
-Exec=kcmshell5 launchfeedback
 
 X-KDE-Library=kcm_launchfeedback
 X-KDE-ParentApp=kcontrol

kcms/mouse/mouse.desktop

 [Desktop Entry]
-Exec=kcmshell5 mouse
 Icon=preferences-desktop-mouse
 Type=Service
 X-KDE-ServiceTypes=KCModule,KCModuleInit

kcms/nightcolor/kcm_nightcolor.desktop

 [Desktop Entry]
 Icon=preferences-desktop-display-nightcolor
-Exec=kcmshell5 kcm_nightcolor
 
 Type=Service
 X-KDE-ServiceTypes=KCModule

kcms/notifications/kcm_notifications.desktop

 [Desktop Entry]
-Exec=kcmshell5 kcm_notifications
 Icon=preferences-desktop-notification-bell
 Type=Service
 X-KDE-ServiceTypes=KCModule

kcms/qtquicksettings/qtquicksettings.desktop

 [Desktop Entry]
-Exec=kcmshell5 qtquicksettings
 Icon=preferences-desktop-locale
 Type=Service
 X-KDE-ServiceTypes=KCModule