Fix VTS test case HidlHalGTest#RadioHidlTest.getIccCardStatus_32bit failed.

Fix VTS test case HidlHalGTest#RadioHidlTest.getIccCardStatus_32bit failed.

In the ril.h, the annotation of gsm_umts_subscription_app_index is "value < RIL_CARD_MAX_APPS, -1 if none".
But in the reference-ril.c, the gsm_umts_subscription_app_index is initialized to RIL_CARD_MAX_APPS.
The VTS test case HidlHalGTest#RadioHidlTest.getIccCardStatus_32bit failed with the reason :"Expected: (cardStatus.gsmUmtsSubscriptionAppIndex) < ((int)RadioConst::CARD_MAX_APPS), actual: 8 vs 8"
gsm_umts_subscription_app_index; /* value < RIL_CARD_MAX_APPS, -1 if none */
cdma_subscription_app_index;     /* value < RIL_CARD_MAX_APPS, -1 if none */
ims_subscription_app_index;      /* value < RIL_CARD_MAX_APPS, -1 if none */

Test:build
Change-Id: I3f7ade93e2f0f7099d934a1b50e01ff04c8c01da