Fix v60001/tprestart subtest failures due to lack of bitmap restarts (code: a)
Fix v60001/tprestart subtest failures due to lack of bitmap restarts (code: a)

In one test run, the last stage of this subtest did not encounter even one bitmap
related restart (code 'a'). In the syslog, a lot of G type restarts were seen
which are indicative of lack of global buffers. So the test is enhanced to have
8 times the default # of global buffers (from 1Ki to 8Ki). That should almost
eliminate the likelihood of G type restarts and increase the likelihood of 'a'
type restarts which this test expects.

While at that, also increased the allocation and extension settings 4 times
from 2Ki to 8Ki to reduce the frequency of DBFILEXT syslog messages. This way
the syslog will most likely have just the 'a' type restarts this test cares about.

nars1/YottaDBtest,nars1/YottaDBtest,nars1/YottaDBtest,nars1/YottaDBtest,nars1/YottaDBtest,nars1/YottaDBtest