feat(adk): auto memory support multi memory store

[N3kox]

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[codecov]

Codecov Report

❌ Patch coverage is 68.24534% with 409 lines in your changes missing coverage. Please review.
⚠️ Please upload report for BASE (alpha/10@fd92075). Learn more about missing BASE report.

Files with missing lines	Patch %	Lines
adk/middlewares/automemory/utils.go	60.74%	188 Missing and 64 partials ⚠️
adk/middlewares/automemory/multistore_backend.go	30.09%	67 Missing and 5 partials ⚠️
adk/middlewares/automemory/automemory.go	82.40%	20 Missing and 18 partials ⚠️
adk/middlewares/automemory/prompt.go	86.76%	26 Missing and 10 partials ⚠️
adk/middlewares/automemory/coordinator.go	80.00%	6 Missing and 5 partials ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##             alpha/10    #1087   +/-   ##
===========================================
  Coverage            ?   81.58%           
===========================================
  Files               ?      186           
  Lines               ?    30538           
  Branches            ?        0           
===========================================
  Hits                ?    24913           
  Misses              ?     3835           
  Partials            ?     1790           

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