Is reference to "God" as a rock unique to Judeo-Christian usage? Throughout the Old Testament God is likened to a “Rock” and within the New Testament the Rock that Moses struck is identified as Christ.

For who is God, save the LORD? and who is a rock, save our God? (2 Samuel 22:32)
And did all drink the same spiritual drink: for they drank of that spiritual Rock that followed them: and that Rock was Christ. (1 Corinthians 10:4)

Was such a metaphor for God as a “rock” unique to Israel, or was that a widespread view of Divinity?
I'm unsure of other religions, but regarding Christianity today, the Bible tells us 


  "Do not fear, nor be afraid; Have I not told you from that time, and
  declared it? You are My witnesses. Is there a God besides Me? Indeed
  there is no other Rock; I know not one. (Isaiah 44:8)


So when Jesus says 


  "on this rock I will build My church, and the gates of Hades shall not
  prevail against it." (Matthew 16:18)


The gates of Hades did not prevail against Jesus, He is the Rock, sinless and risen! Many Christian denominations today still consider Jesus the rock.  Popular hymns written long ago such as "Rock of Ages" also show that individuals many years ago saw this as true.