[M1] Fix test_crm_available for 7050C-C28S16 (#21010)

What is the motivation for this PR?
Fix test_crm_available for 7050C-C28S16

How did you do it?
Update threshold.

How did you verify/test it?
Verified on M1-44 Arista-7050C testbed.

Signed-off-by: selldinesh <[email protected]>

Author: lizhijianrd

tests/crm/test_crm_available.py

@@ -19,10 +19,12 @@
     'Arista-7050CX3-32S-C32': 255,
     'arista-7050cx3-32s-s128': 255,
     'arista-7050cx3-32s-c6s104': 255,
+    'arista-7050cx3-32s-c28s16': 255,
     'arista-7050cx3-32c-c28s4': 255,
     'Arista-7050CX3-32c-C32': 255,
     'arista-7050cx3-32c-s128': 255,
     'arista-7050cx3-32c-c6s104': 255,
+    'arista-7050cx3-32c-c28s16': 255,
 }
 
 DEFAULT_NEXTHOP_THRESHOLD = 256