Fix the maximum concurrent number of capabilities request doesn't work

When the request is running, it doesn't be put to the executing collection.
Therefore, the checking function always think that there is no request running.

Bug: 185383485
Test: atest -c CtsTelephonyTestCases:android.telephony.ims.cts.RcsUceAdapterTest
Change-Id: I1bf563b69f7d9c08413ad19e12b4eb2880c9c74a