Make some methods static

To make it more obvious that these are only used by APacketSource

Test: build
Change-Id: I8f585cfb4bb4123eb7da4aedade5510d736fa597
diff --git a/media/libstagefright/rtsp/APacketSource.cpp b/media/libstagefright/rtsp/APacketSource.cpp
index 68f8bdd..201a5df 100644
--- a/media/libstagefright/rtsp/APacketSource.cpp
+++ b/media/libstagefright/rtsp/APacketSource.cpp
@@ -219,7 +219,7 @@
     return csd;
 }
 
-sp<ABuffer> MakeAACCodecSpecificData(const char *params) {
+static sp<ABuffer> MakeAACCodecSpecificData(const char *params) {
     AString val;
     CHECK(GetAttribute(params, "config", &val));
 
@@ -257,7 +257,7 @@
 }
 
 // From mpeg4-generic configuration data.
-sp<ABuffer> MakeAACCodecSpecificData2(const char *params) {
+static sp<ABuffer> MakeAACCodecSpecificData2(const char *params) {
     AString val;
     unsigned long objectType;
     if (GetAttribute(params, "objectType", &val)) {