remove duplicate update logic in gateway lwm2m

[rhoninl]

What this PR does / why we need it:
Auto update is same with InActvityMonitor in udpOptions, both of them will send update request with a interval. but the InactivityMonitor have reconnect logic in it, so remove duplicate action autoUpdate to avoid send too many update requrest.
Will this PR make the community happier?
yes
Which issue this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close that issue when PR gets merged): fixes #

How is this PR tested

• unit test
• e2e test
• other (please specify)

Special notes for your reviewer:

Release note:

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 1 line in your changes missing coverage. Please review.

Project coverage is 33.06%. Comparing base (cfc8fd1) to head (79ba961).

Files with missing lines	Patch %	Lines
pkg/gateway/lwm2m/client/lwm2m.go	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1092      +/-   ##
==========================================
+ Coverage   32.96%   33.06%   +0.10%     
==========================================
  Files          55       55              
  Lines        4875     4860      -15     
==========================================
  Hits         1607     1607              
+ Misses       3128     3113      -15     
  Partials      140      140              

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