Not all. Hinduism gives freedom for people to think on their own. It's not some block of people all thinking exactly the same way. That's a beauty of Hinduism that other faiths don't have so much of. So you'd have to go around and ask each person what they truly believed.
Do the Ammadiyas believe that Mirza Akmad was Kalki, in the same way the Baha'is believe Baha'u'llah was?
There is no likeness/same way between Ahmadiyya and Bahaism. Bahaism is a new Religion while Ahmadiyya and Claims of Mirza Ghulam Ahmad are as a Successor of Muhammad and within Islam and within the teaching of Quran, please?
That said, Kalki Avatar is the Second Coming of Krishna so there is no difference in them.
Yes, Mirza Ghulam Ahmad did claim being Second Coming of Krisha:
"Finally, let it be clear that my advent in the present age is not for the reformation of the Muslims alone, but I have come to reform the people of all the three religions: Muslims, Christians and Hindus. Just as God has appointed me the Promised Messiah for the Muslims and Christians, so am I the Avatar for the Hindus. For the past twenty years or so, I have been proclaiming that just as I have appeared in the spirit of the Messiah son of Mary (as( for the purpose of removing sins which have filled the earth, so have I come as Raja Krishna—one of the greatest Avatars of the Hindu faith. In other words, I am the same person by virtue of spiritual reality. This is no fancy or speculation on my part. The God of heaven and earth has revealed to me, not once but a number of times, that for the Hindus I am Krishna and for the Muslims and Christians I am the Promised Messiah. I know that the ignorant Muslims, on hearing this, will immediately say that by assuming the name of a kafir, I have openly accepted disbelief. But this revelation is from God and I have no choice but to proclaim it. Today it is for the first time that I am announcing it before such a large gathering, for those who are from God are never afraid of the reproaches of faultfinders. Let it be clear that Raja Krishna, according to what has been revealed to me, was such a truly great man that it is hard to find his like among the Rishis and Avatars of the Hindus. He was an Avatar—i.e., Prophet—of his time upon whom the Holy Spirit would descend from God. He was from God, victorious and prosperous. He cleansed the land of the Aryas from sin and was in fact the Prophet of his age whose teaching was later corrupted in numerous ways. He was full of love for God, a friend of virtue and an enemy of evil. It was God’s promise that, in the latter days, He would send someone, i.e., an Avatar, in his image. Hence this promise has been fulfilled with my coming. Among other revelations regarding myself, I also received this revelation: 31* Hence, I love Krishna because I have come in his image. Another resemblance between the two of us is that the same qualities that have been attributed to Krishna (for instance, his being the destroyer of sin, the consoler, and the nourisher of the poor) are also the qualities of the Promised Messiah. From the spiritual point of view, therefore, Krishna and Promised Messiah are one and the same; it is only the regional terminology that is different."
Page 30-40
https://www.alislam.org/library/books/LectureSialkot.pdf
*31 O’ Krishna, slayer of swine and protector of cows, thy praise is recorded in the Gita. [Publishers]
Regards