* stable-5.2:
Prepare 5.1.9-SNAPSHOT builds
JGit v5.1.8.201906050907-r
Test detecting modified packfiles
Enhance fsTick() to use filesystem timer resolution
Add debug trace to measure time needed to open pack index
Extend FileSnapshot for packfiles to also use checksum to detect changes
Wait opening new packfile until it can't be racy anymore
Avoid null PackConfig in GC
Add FileSnapshot test testing recognition of file size changes
Capture reason for result of FileSnapshot#isModified
Skip FileSnapshotTest#testSimulatePackfileReplacement on Windows
Tune max heap size for tests
Fix FileSnapshotTest.testNewFileNoWait() to match its javadoc
ObjectDirectory: fix closing of obsolete packs
Include filekey file attribute when comparing FileSnapshots
Measure file timestamp resolution used in FileSnapshot
Fix FileSnapshot's consideration of file size
Fix API problem filters
Fix API problem filters
Change-Id: Id79a3a19f9a31dff94d10a406c2b6e08a506931a
60d65bbd22