[Motion] Fixed documentation

Resolves #1490

GIT_ORIGIN_REV_ID=320582f0e3c652c4d0f2e510659eed78c6f50248
PiperOrigin-RevId: 322177658

Author: NUmeroAndDev

docs/theming/Motion.md

@@ -156,7 +156,7 @@ transition to the the provided `Hold` transition.
 
 ```kt
 // FragmentA.kt
-fun onCreate(savedInstanceState: Bundle?) {
+override fun onCreate(savedInstanceState: Bundle?) {
   super.onCreate(savedInstanceState)
 
   // Fragment A’s exitTransition can be set any time before Fragment A is