logd: ro.config.low_ram set buffer size to 64K

Bug: 25792367
Change-Id: Icae85a7de70b3a71f89b2bf8c80866649f727177
diff --git a/logd/LogBuffer.cpp b/logd/LogBuffer.cpp
index 1e4f3b0..5922f16 100644
--- a/logd/LogBuffer.cpp
+++ b/logd/LogBuffer.cpp
@@ -100,6 +100,11 @@
     unsigned long default_size = property_get_size(global_tuneable);
     if (!default_size) {
         default_size = property_get_size(global_default);
+        if (!default_size) {
+            default_size = property_get_bool("ro.config.low_ram", false) ?
+                LOG_BUFFER_MIN_SIZE : // 64K
+                LOG_BUFFER_SIZE;      // 256K
+        }
     }
 
     log_id_for_each(i) {