Fix a bunch of repeated reads of a ro.* property

SystemProperties.get() is not particularly fast,
especially if a string is returned. Since ro.* values
are unable to be changed, there's no need to
continously re-query them. Cache the value at
static init time to trivially fix this.

Test: refactoring CL.
Change-Id: Iccb021d3cb2ba3a4a1d0048ddec6811bb7409eec
(cherry picked from commit aa67f684ff43c81e3280c846245ec6ebe907787e)
diff --git a/preloaded-classes b/preloaded-classes
index 805a1c9..42f290e 100644
--- a/preloaded-classes
+++ b/preloaded-classes
@@ -2542,6 +2542,7 @@
 com.android.internal.os.RuntimeInit$Arguments
 com.android.internal.os.RuntimeInit$KillApplicationHandler
 com.android.internal.os.RuntimeInit$LoggingHandler
+com.android.internal.os.RoSystemProperties
 com.android.internal.os.SamplingProfilerIntegration
 com.android.internal.os.SomeArgs
 com.android.internal.os.Zygote