better validation lengths of strings in ID3 tags

Validate lengths on strings in ID3 tags, particularly around 0.
Also added code to handle cases when we can't get memory for
copies of strings we want to extract from these tags.

Affects L/M/N/master, same patch for all of them.

Bug: 30744884
Change-Id: I2675a817a39f0927ec1f7e9f9c09f2e61020311e
Test: play mp3 file which caused a <0 length.
(cherry picked from commit d23c01546c4f82840a01a380def76ab6cae5d43f)

ID3::Iterator::Iterator(const ID3 &parent, const char *id)
 : mParent(parent),
      mID(NULL),
      mOffset(mParent.mFirstFrameOffset),
      mFrameData(NULL),
      mFrameSize(0) {
 if (id) {
        mID = strdup(id);
 }

    findFrame();
}

ID3::Iterator::Iterator(const ID3 &parent, const char *id)
 : mParent(parent),
      mID(NULL),
      mOffset(mParent.mFirstFrameOffset),
      mFrameData(NULL),
      mFrameSize(0) {
 if (id) {
        mID = strdup(id);
 }

    findFrame();
}
