Java:
CTRL+ “-” / CTRL+ “+”: Collapse / Expand current code region
CTRL+N: generate… (New constructor, getter and setter…)
CTRL+ALT+M: Close All
CTRL+ALT+N: Close All but this (Close others)
CTRL+Shift+T: New terminal Tab (Bottom terminal of Android Studio)
CTRL+ALT+D: Debug
CTRL+F9: Build / Make project
F7: Step into
F8: Step over
F9: Continue
XML:
CTRL+Shift+I: auto-indent (also available in Java)