Clean up overloading of FileExists

FileExists is used for directories and also returns false for 0-length
files. Both behaviors are a bit surprising, so split it into:

FileHasContent
DirExists

Test: Local build
Bug: 110097226
Change-Id: Ic6caf67a0c9194a44a75a5b5f1cb2a427312d8b4
Merged-In: Ic6caf67a0c9194a44a75a5b5f1cb2a427312d8b4
(cherry picked from commit 85b72a547709b77617d0861302ed3f9acdd6288d)
1 file changed
tree: c9337871e8030f5b233342a9040b23d9768a3f10
  1. common/
  2. guest/
  3. host/
  4. tests/
  5. tools/
  6. Android.bp
  7. Android.mk
  8. OWNERS