Enable the simultaneous use of Flex delegate and other delegate
Can you add tests in subgraph_test to show what this fixes? Hi @robert-kalmar This PR is in draft, any update on this? Please. Thank you!
 Hi @gbaned , 
I put the PR into the draft due to @qukhan  request for the test case. We have a test case with one of our external delegate, however still investigating how to test it in isolation in TFLite. 

 Hi @robert-kalmar This PR is in draft, any update on this? Please. Thank you! Hi @robert-kalmar Any update on this PR? Please. Thank you!
Fixes problem when Flex Delegate and other (e.g. external) delegate is used. 