logd: logcat: Add persist.logd.size group of properties

- logd Add persist.logd.size (global), persist.logd.size.<logid>
- logcat report a more flexible multiplier in -g command.

Bug: 14563261
Bug: 14469172
Change-Id: Ie389caa14ad3ae3d4a3a3cc463425bb9dbc5e483
diff --git a/logd/README.property b/logd/README.property
index 5d92d09..f4b3c3c 100644
--- a/logd/README.property
+++ b/logd/README.property
@@ -10,3 +10,16 @@
                                          minimum domain socket network FIFO
                                          size (see source for details) based
                                          on typical load (logcat -S to view)
+persist.logd.size          number 256K   default size of the buffer for all
+                                         log ids at initial startup, at runtime
+                                         use: logcat -b all -G <value>
+persist.logd.size.main     number 256K   Size of the buffer for the main log
+persist.logd.size.system   number 256K   Size of the buffer for the system log
+persist.logd.size.radio    number 256K   Size of the buffer for the radio log
+persist.logd.size.event    number 256K   Size of the buffer for the event log
+persist.logd.size.crash    number 256K   Size of the buffer for the crash log
+
+NB:
+- number support multipliers (K or M) for convenience. Range is limited
+  to between 64K and 256M for log buffer sizes. Individual logs override the
+  global default.