Relax inode usage estimate.

The current inode usage estimate applies a factor (1.04x) to account for
differences between the directory and file count and what mkfs.ext4
produces. Bump this to 1.06x to allow more leniency.

This increases bramble partition sizes by 32KB total.

Bug: 182365132
Test: manual test
Change-Id: I9ade82cb89422e31ae8c5df9fff31157e88278c5

tools/releasetools/build_image.py

@@ -73,9 +73,9 @@ def GetInodeUsage(path):
   """
   cmd = ["find", path, "-print"]
   output = common.RunAndCheckOutput(cmd, verbose=False)
-  # increase by > 4% as number of files and directories is not whole picture.
+  # increase by > 6% as number of files and directories is not whole picture.
   inodes = output.count('\n')
-  spare_inodes = inodes * 4 // 100
+  spare_inodes = inodes * 6 // 100
   min_spare_inodes = 12
   if spare_inodes < min_spare_inodes:
     spare_inodes = min_spare_inodes