`app` is silly but good example to multi project s...

# kobalt

[fboldog]

app is silly but good example to multi project structure simple smile
for example our version

- projectDir
-- p1 (java)
-- p2 (depends on p1 - java)
-- p3 (depends on p2 - android - variants - internal / external)
-- p4 (depends on p3 - android)