[FRR template]Add missing exit to avoid config nht via default route …

…in vrf (sonic-net#19587)

Why I did it
The 'ip nht resolve-via-default' is configured in vrf config by mistake instead of the global setting when vrf is configured causing the bgpl cannot to be established.

Work item tracking
Microsoft ADO (number only): 28726407
How I did it
Add the missing 'exit' line in FRR zebra.interfaces.conf.j2 file to exit vrf config block and ensure the 'ip nht resolve-via-default' is configured in the global setting.

dockers/docker-fpm-frr/frr/zebra/zebra.interfaces.conf.j2

@@ -4,6 +4,7 @@
 {%   for vnet_name, vnet_metadata in VNET.items() %}
 vrf {{ vnet_name }}
 vni {{ vnet_metadata['vni'] }}
+exit
 !
 {%   endfor %}
 {%  endif %}

src/sonic-bgpcfgd/tests/data/sonic-cfggen/zebra/zebra.conf

@@ -22,9 +22,11 @@ log facility local4
 !
 vrf First
 vni 10
+exit
 !
 vrf Second
 vni 20
+exit
 !
 ! Enable nht through default route
 ip nht resolve-via-default

src/sonic-config-engine/tests/sample_output/py2/t2-chassis-fe-vni-zebra.conf

@@ -22,6 +22,7 @@ log facility local4
 !
 vrf VnetFE
 vni 9000
+exit
 !
 !
 ! Enable nht through default route

src/sonic-config-engine/tests/sample_output/py2/t2-chassis-fe-zebra.conf

@@ -22,6 +22,7 @@ log facility local4
 !
 vrf VnetFE
 vni 8000
+exit
 !
 !
 ! Enable nht through default route

src/sonic-config-engine/tests/sample_output/py3/t2-chassis-fe-vni-zebra.conf

@@ -22,6 +22,7 @@ log facility local4
 !
 vrf VnetFE
 vni 9000
+exit
 !
 !
 ! Enable nht through default route

src/sonic-config-engine/tests/sample_output/py3/t2-chassis-fe-zebra.conf

@@ -22,6 +22,7 @@ log facility local4
 !
 vrf VnetFE
 vni 8000
+exit
 !
 !
 ! Enable nht through default route

src/sonic-config-engine/tests/sample_output/t2-chassis-fe-pc-zebra.conf

@@ -10,6 +10,7 @@ enable password zebra
 !
 vrf VnetFE
 vni 8000
+exit
 !
 !
 ! Enable nht through default route