Fix BridgeEpollController to handles EAGAIN correctly

When reading/writing proxy FD, if it returns EAGAIN,
BridgeEpollController updates epoll entries to observe specific FD
events. Before updating epoll entries, BridgeEpollController checks if
it really needs to update by comparing |state_| and |last_state_|.
|last_state_| has not been updated correctly so it resulted in wrong
epoll settings and keeps blocking the event loop.

Bug: 134104939
Test: atest libappfuse_test
Change-Id: I1c4a0164c1c016baf24ecfd523476ced981d3b28