Fix already built incompatible payload thrown error

[TharmiganK]

Purpose

Fix already built incompatible payload thrown NPE due to unhandled exception

Fixes ballerina-platform/ballerina-standard-library/issues/1600

Checklist

• Linked to an issue
• Updated the changelog
• Added tests

[codecov]

Codecov Report

Merging #513 (646e8d8) into master (45651fc) will increase coverage by 0.00%.
The diff coverage is 87.50%.

@@            Coverage Diff            @@
##             master     #513   +/-   ##
=========================================
  Coverage     80.87%   80.88%           
  Complexity       67       67           
=========================================
  Files           318      318           
  Lines         16510    16512    +2     
  Branches       3898     3899    +1     
=========================================
+ Hits          13352    13355    +3     
+ Misses         2453     2450    -3     
- Partials        705      707    +2     

Impacted Files	Coverage Δ
...t/http/nativeimpl/ExternHttpDataSourceBuilder.java	84.34% <87.50%> (+0.27%)	⬆️
...sport/message/ClientRemoteFlowControlListener.java	52.63% <0.00%> (-15.79%)	⬇️
...ansport/message/DefaultBackPressureObservable.java	64.28% <0.00%> (-7.15%)	⬇️
...ransport/message/DefaultFullHttpMessageFuture.java	96.00% <0.00%> (-4.00%)	⬇️
...transport/message/Http2InboundContentListener.java	51.28% <0.00%> (-2.57%)	⬇️
...nsport/contractimpl/DefaultHttpResponseFuture.java	73.37% <0.00%> (-1.30%)	⬇️
http-ballerina/http_response.bal	86.13% <0.00%> (+0.84%)	⬆️
...alang/net/http/service/signature/ParamHandler.java	87.50% <0.00%> (+1.47%)	⬆️
...mpl/listener/states/http2/ReceivingEntityBody.java	70.00% <0.00%> (+15.00%)	⬆️

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