Anyway, as Orthodox Christians, it is essential that we trust the tradition of the church.
I hope the Orthodox tradition does not stipulate that we pray to Allah in our liturgies.
So far I have come across no Church father that said: "Allah is the same as Adonai YHWH" or "Allah means the God in Arabic, so there is nothing wrong with using that name in our Church".
Theodore of Qurah, the disciple of St. John of Damascus, the first major Arabic Father (previous Arab Fathers, like St. John of Damascus, wrote in Greek, and all the Arab Fathers after him. He uses Allah all the time as it is the Arabic word for "God" (the definite article functions in Arabic as capitalization, which we do not have in Arabic), predating Muhammad for generations, the cognate of all Semitic languages word for God.
One of those cognates, 'el, is used throughout in the Hebrew Bible for God all over the place, although it is also the name of a Canaanite deity:
Cf. Eli, Eli, lama sabakhthani. Good enough for Jesus, good enough for me.
St. Ephraim the Syrian and all the Syriac Fathers. He says "alaha" (-a is the Aramaic definite article, equivalent to the al- of Arabic). Aramaic alaha would influence Arabic Christian usage, as elsewhere (the words for prayer, fasting, etc in even the Quran (another borrowing from Syriac: its the word for "Lectionary") are Aramaic/Syriac loans).