Description:Modify some discription of reference/apis/js-apis-inner-application-uiAbilityContext.md

Sig:SIG_ApplicationFramework
Feature or BugFix: Feature
Binary Source: No
Signed-off-by: Nzhangyafei.echo <zhangyafei12@huawei.com>
Change-Id: I628d192b2b60a21fb1b41cd719759765504131f6