santoni: Add feature flag for FEATURE_IPSEC_TUNNELS

This commit adds the IPSEC_TUNNELS feature flag, with XFRM Interfaces
used as the implementation of choice.

Bug: 159672044
Test: Compiles, passes tunnel-mode CTS tests
Test: adb shell pm list features
Change-Id: I850013c554a6cd009d74eb1f61c08147f593cd26

device.mk

@@ -68,6 +68,7 @@ PRODUCT_COPY_FILES += \
     frameworks/native/data/etc/android.hardware.vulkan.level-0.xml:$(TARGET_COPY_OUT_VENDOR)/etc/permissions/android.hardware.vulkan.level-0.xml \
     frameworks/native/data/etc/android.hardware.vulkan.version-1_1.xml:$(TARGET_COPY_OUT_VENDOR)/etc/permissions/android.hardware.vulkan.version-1_1.xml \
     frameworks/native/data/etc/android.hardware.vulkan.compute-0.xml:$(TARGET_COPY_OUT_VENDOR)/etc/permissions/android.hardware.vulkan.compute-0.xml \
+    frameworks/native/data/etc/android.software.ipsec_tunnels.xml:$(TARGET_COPY_OUT_VENDOR)/etc/permissions/android.software.ipsec_tunnels.xml \
     frameworks/native/data/etc/android.hardware.wifi.xml:$(TARGET_COPY_OUT_VENDOR)/etc/permissions/android.hardware.wifi.xml \
     frameworks/native/data/etc/android.hardware.wifi.passpoint.xml:$(TARGET_COPY_OUT_VENDOR)/etc/permissions/android.hardware.wifi.passpoint.xml \
     frameworks/native/data/etc/android.hardware.wifi.direct.xml:$(TARGET_COPY_OUT_VENDOR)/etc/permissions/android.hardware.wifi.direct.xml \