Adding eSIM option is not disabled if the current country is not in the allowed list

When both stack 1(pSIM) and stack 2(eSIM) are not available, stack 1 starts for emergency calls only. For eSIM, modem keeps on stopped state due to power consumption concern which is as per DSDS design.
Modified the logic to not call platform API if the countryCode is empty.

Bug: 231952356
Test: 1) Manually verified on C10P10 and Pixel 4a Device and eSIM option is enabled.
2) Modified not allowed country list and verified the eSIM option is disabled.

Change-Id: I99750f80fb2e2e180950b743ecbbbcb7a912528f