Previously in MultiInputVideoGraph, each VFP would destroy the shared
eglContext, such that the same eglContext object is destroyed multiple times.
Adding a flag to disallow this.
The alternative being we could add a flag on the VFP constructor, but I think
that is too subscriptive (meaning if we later might want to add another boolean
to control another GL behaviour, multiple booleans would make the class less
reason-able), and would incur a lot of code changes at places.
PiperOrigin-RevId: 660354367