[202405][fastboot] Notify SAI that fastboot is done

[Junchao-Mellanox]

Backport #1396 to 202405

Why I did this

Notify SAI that fastboot is done

How I did this

Set SAI_SWITCH_ATTR_FAST_API_ENABLE to false when fastboot is done

How I verify this

Manual test

[bingwang-ms]

@Junchao-Mellanox This PR caused failure in PR test in submodule update. sonic-net/sonic-buildimage#21001
The error message points to the code changed in this PR. Can you take a look?

TestSyncd.cpp:16:23: error: 'empty' is not a type
     MOCK_METHOD(bool, empty, (), (override));
                       ^~~~~
TestSyncd.cpp:16:30: error: expected identifier before '(' token
     MOCK_METHOD(bool, empty, (), (override));
                              ^
TestSyncd.cpp:16:34: error: expected identifier before '(' token
     MOCK_METHOD(bool, empty, (), (override));
                                  ^
TestSyncd.cpp:16:44: error: ISO C++ forbids declaration of 'MOCK_METHOD' with no type [-fpermissive]
     MOCK_METHOD(bool, empty, (), (override));
                                            ^
TestSyncd.cpp:17:23: error: 'pop' is not a type
     MOCK_METHOD(void, pop, (swss::KeyOpFieldsValuesTuple& kco, bool initViewMode), (override));
                       ^~~
TestSyncd.cpp:17:28: error: expected identifier before '(' token
     MOCK_METHOD(void, pop, (swss::KeyOpFieldsValuesTuple& kco, bool initViewMode), (override));
                            ^
TestSyncd.cpp:17:84: error: expected identifier before '(' token
     MOCK_METHOD(void, pop, (swss::KeyOpFieldsValuesTuple& kco, bool initViewMode), (override));
                                                                                    ^
TestSyncd.cpp:17:94: error: ISO C++ forbids declaration of 'MOCK_METHOD' with no type [-fpermissive]
     MOCK_METHOD(void, pop, (swss::KeyOpFieldsValuesTuple& kco, bool initViewMode), (override));
                                                                                              ^
TestSyncd.cpp:17:17: error: invalid use of type 'void' in parameter declaration
     MOCK_METHOD(void, pop, (swss::KeyOpFieldsValuesTuple& kco, bool initViewMode), (override));
                 ^~~~