audio: Fix the type used for timekeeping

On 32-bit builds, the 'long' type is 32 bit. Thus, it can not
be used to store the value returned from 'uptimeNanos'.

Bug: 318055805
Test: atest CtsMediaAudioTestCases
Change-Id: I4abf72415b7241728d3ddb1d11043dfd59a8d08a
diff --git a/audio/aidl/default/r_submix/StreamRemoteSubmix.cpp b/audio/aidl/default/r_submix/StreamRemoteSubmix.cpp
index df706ac..3ee354b 100644
--- a/audio/aidl/default/r_submix/StreamRemoteSubmix.cpp
+++ b/audio/aidl/default/r_submix/StreamRemoteSubmix.cpp
@@ -138,7 +138,7 @@
                                     : outWrite(buffer, frameCount, actualFrameCount));
     const long bufferDurationUs =
             (*actualFrameCount) * MICROS_PER_SECOND / mContext.getSampleRate();
-    const long totalDurationUs = (::android::uptimeNanos() - mStartTimeNs) / NANOS_PER_MICROSECOND;
+    const auto totalDurationUs = (::android::uptimeNanos() - mStartTimeNs) / NANOS_PER_MICROSECOND;
     mFramesSinceStart += *actualFrameCount;
     const long totalOffsetUs =
             mFramesSinceStart * MICROS_PER_SECOND / mContext.getSampleRate() - totalDurationUs;
@@ -274,8 +274,8 @@
     char* buff = (char*)buffer;
     size_t actuallyRead = 0;
     long remainingFrames = frameCount;
-    const long deadlineTimeNs = ::android::uptimeNanos() +
-                                getDelayInUsForFrameCount(frameCount) * NANOS_PER_MICROSECOND;
+    const int64_t deadlineTimeNs = ::android::uptimeNanos() +
+                                   getDelayInUsForFrameCount(frameCount) * NANOS_PER_MICROSECOND;
     while (remainingFrames > 0) {
         ssize_t framesRead = source->read(buff, remainingFrames);
         LOG(VERBOSE) << __func__ << ": frames read " << framesRead;