Added a new system properties for IWLAN operation mode

Added a new flag to specify the IWLAN operation mode. Also
allowed this system properties for vendor native service to
access.

Test: Manual
Bug: 73659459
Change-Id: I23197e451557fae36a0cc5da4b50b3a00f9233dc

public/property_contexts

@@ -130,6 +130,7 @@ ro.storage_manager.enabled u:object_r:exported3_default_prop:s0 exact bool
 ro.telephony.call_ring.multiple u:object_r:exported3_default_prop:s0 exact bool
 ro.telephony.default_cdma_sub u:object_r:exported3_default_prop:s0 exact int
 ro.telephony.default_network u:object_r:exported3_default_prop:s0 exact string
+ro.telephony.iwlan_operation_mode u:object_r:exported3_default_prop:s0 exact int
 ro.url.legal u:object_r:exported3_default_prop:s0 exact string
 ro.url.legal.android_privacy u:object_r:exported3_default_prop:s0 exact string
 ro.vendor.build.security_patch u:object_r:vendor_security_patch_level_prop:s0 exact string